Copolymer and composition

ABSTRACT

A copolymer includes a repeating unit represented by Formula (I); and a repeating unit represented by Formula (II), in Formula (I), R 1  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R 2  represents an alkyl group having 1 to 20 carbon atoms and having at least one fluorine atom as a substituent, or a group including —Si(R a3 )(R a4 )O—; L represents a divalent linking group as defined herein; and R a3  and R a4  each independently represent an alkyl group as defined herein, in Formula (II), R 10  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R 11  and R 12  each independently represent a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group; R 11  and R 12  may be linked to each other; and X 1  represents a divalent linking group.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of International Application No.PCT/JP2017/023078 filed on Jun. 22, 2017, and claims priorities fromJapanese Patent Application No. 2016-126440 filed on Jun. 27, 2016,Japanese Patent Application No. 2016-193814 filed on Sep. 30, 2016 andJapanese Patent Application No. 2017-013698 filed on Jan. 27, 2017, theentire disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a copolymer and a composition.

2. Description of the Related Art

An optical film, which is a kind of functional film, is used in apolarizing plate.

A polarizing plate is used as a member of a liquid crystal display (LCD)device and an organic electroluminescent diode (organic EL) display(OLED), and plays an important role in display performance. An ordinarypolarizing plate has a configuration in which an optical film islaminated on one surface or both surfaces of a polarizer of a polyvinylalcohol (PVA)-based resin processed for adsorption orientation with adichroic dye such as an iodine complex or the like.

In recent years, an increase in size, a reduction in thickness, andflexibilization of a display device have been proceeded. Accordingly, apolarizing plate is required to have a function different from that ofthe related art and is also required to be thin.

In order to reduce the thickness of a polarizing plate, it is requiredto reduce the thickness of an optical film constituting the polarizingplate. For example, WO2014/199934A discloses a method in which a coatingfilm is provided on a temporary support, a polarizer is laminated on thecoating film, and the temporary support is then peeled off from thecoating film to prepare a polarizing plate having a coating film with afilm thickness of less than 10 μm laminated thereon.

In addition, a fluorine-containing copolymer or a copolymer having asiloxane bond may be added to a composition for forming a functionalfilm as a leveling agent.

SUMMARY OF THE INVENTION

WO2014/199934A discloses a coating film mainly formed of a cyclo olefinpolymer and according to the study of the present inventors, it has beenfound that the coating film is a coating film which is excellent inpeelability from the temporary support and has a low birefringence, butthis coating film has insufficient adhesiveness with a polarizer.

In general, the function of the film, which is a feature, is largelydependent on the main material of the film. However, the main materialis not necessarily suitable for adhesion with other layers, films, orother articles, and the main material is rather disadvantageous foradhesion in many cases.

In view of the above problems, an object of the present invention, thatis, an object to be achieved by the present invention is to provide acopolymer capable of sufficiently bonding a functional film with otherlayers, films, or other articles, and a composition containing thecopolymer.

The present inventors have found that the above object can be achievedby the following action of the copolymer of the present invention.

That is, in a case of bonding a functional film containing the copolymerof the present invention with other layers, films, or other articles,the copolymer of the present invention contained in the functional filmcan be unevenly distributed on the surface of the functional film by theaction of a repeating unit represented by Formula (I). Since a repeatingunit represented by Formula (II) in the copolymer forms a crosslinkedreaction product with other layers, films, or other articles, it isconsidered that the adhesiveness between the functional film and otherlayers, films, or other articles can be enhanced.

Accordingly, the present invention which is specific means for achievingthe above object is as follows.

<1> A copolymer comprising: a repeating unit represented by Formula (I);and a repeating unit represented by Formula (II),

in Formula (I), R¹ represents a hydrogen atom or an alkyl group having 1to 20 carbon atoms; R² represents an alkyl group having 1 to 20 carbonatoms and having at least one fluorine atom as a substituent, or a groupincluding —Si(R^(a3))(R^(a4))O—; L represents a divalent linking groupcomprising at least one selected from the group consisting of —O—,—(C═O)O—, —O(C═O)—, a divalent aliphatic chain group and a divalentaliphatic cyclic group; and R^(a3) and R^(a4) each independentlyrepresent an alkyl group having 1 to 12 carbon atoms which may have asubstituent,

in Formula (II). R¹⁰ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms; R¹¹ and R¹² each independently represent ahydrogen atom, a substituted or unsubstituted aliphatic hydrocarbongroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heteroaryl group; R¹¹ and R¹² may be linked to each other;and X¹ represents a divalent linking group.

<2> The copolymer according to <1>, in which R² of the repeating unitrepresented by Formula (I) represents an alkyl group having 1 to 20carbon atoms and having at least one fluorine atom as a substituent.

<3> The copolymer according to <1> or <2>, in which the repeating unitrepresented by Formula (I) is a repeating unit represented by Formula(III),

in Formula (III), R¹ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms; ma and na each independently represent an integerof 1 to 20; and X represents a hydrogen atom or a fluorine atom.

<4> The copolymer according to any one of <1> to <3>, in which X¹ of therepeating unit represented by Formula (II) includes at least one linkinggroup selected from —(C═O)O—, —O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—,—O(C═O)—NH—, —O(C═O)—O—, and —CH₂— and has 7 or more carbon atoms.

<5> The copolymer according to any one of <1> to <4>, in which therepeating unit represented by Formula (II) is a repeating unitrepresented by Formula (V),

in Formula (V), R¹⁰ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms; R¹¹ and R¹² each independently represent ahydrogen atom, a substituted or unsubstituted aliphatic hydrocarbongroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heteroaryl group; and R¹¹ and R¹² may be linked to eachother; X¹¹ represents a divalent linking group comprising at least oneselected from the group consisting of —(C═O)O—, —O(C═O)—, —(C═O)NH—,—O—, —CO— and —CH₂—; and X¹² represents a divalent linking groupincluding at least one linking group selected from —(C═O)O—, —O(C—O)—,—(C═O)NH—, —O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂— andincluding at least one substituted or unsubstituted aromatic ring; and atotal number of carbon atoms of X¹¹ and X¹² is 7 or more.

<6> The copolymer according to any one of <1> to <5>, in which R¹¹ andR¹² of the repeating unit represented by Formula (II) or (V) represent ahydrogen atom.

<7> The copolymer according to any one of <1> to <6>, furthercomprising: a thermally crosslinking group.

<8> A composition comprising: the copolymer according to any one of <1>to <7>.

According to the present invention, it is possible to provide acopolymer capable of sufficiently bonding a functional film with otherlayers, films, or other articles, and a composition containing thecopolymer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described in detail.

The numerical range which is shown by “to” used in the presentspecification means the range including the numerical values describedbefore and after “to” as the lower limit and the upper limit,respectively.

In the present specification, the expression “(meth)acrylic group” isused as the concept including “either or both of an acrylic group and amethacrylic group”. The same applies to “(meth)acrylic acid”.“(meth)acrylamide”, “(meth)acryloyl group” and the like.

[Copolymer (a)]

A copolymer of the present invention (hereinafter, also referred to as“copolymer (a)”) includes a repeating unit represented by Formula (I)and a repeating unit represented by Formula (II).

In Formula (I), R¹ represents a hydrogen atom or an alkyl group having 1to 20 carbon atoms, R² represents an alkyl group having 1 to 20 carbonatoms and having at least one fluorine atom as a substituent, or a groupincluding —Si(R^(a3))(R^(a4))O—, and L represents a divalent linkinggroup comprising at least one selected from the group consisting of —O—,—(C═O)O—, —O(C═O)—, a divalent aliphatic chain group, and a divalentaliphatic cyclic group. R^(a3) and R^(a4) each independently representan alkyl group having 1 to 12 carbon atoms which may have a substituent.

In Formula (II), R¹⁰ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms, R¹¹ and R¹² each independently represent ahydrogen atom, a substituted or unsubstituted aliphatic hydrocarbongroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heteroaryl group, and R¹¹ and R¹² may be linked to eachother. X¹ represents a divalent linking group.

In Formula (I), R¹ represents a hydrogen atom or an alkyl group having 1to 20 carbon atoms, preferably represents a hydrogen atom or an alkylgroup having 1 to 10 carbon atoms, more preferably represents a hydrogenatom or an alkyl group having 1 to 4 carbon atoms, and even morepreferably represents a hydrogen atom or a methyl group.

In Formula (I), R² preferably represents an alkyl group having 1 to 20carbon atoms and having at least one fluorine atom as a substituent(fluoroalkyl group), more preferably represents a fluoroalkyl grouphaving 1 to 18 carbon atoms, and even more preferably represents afluoroalkyl group having 2 to 15 carbon atoms. In addition, the numberof fluorine atoms in the fluoroalkyl group is preferably 1 to 25, morepreferably 3 to 21, and most preferably 5 to 21.

In Formula (I), L represents a divalent linking group comprising atleast one selected from the group consisting of —O—, —(C═O)O—, —O(C═O)—,a divalent aliphatic chain group, and a divalent aliphatic cyclic group.—(C═O)O— represents that the carbon atom on the R¹ side is bonded withC═O and R² is bonded with O, and —O(C═O)— represents that the carbonatom on the R¹ side is bonded with O and R² is bonded with C═O.

The divalent aliphatic chain group represented by L is preferably analkylene group having 1 to 20 carbon atoms and more preferably analkylene group having 1 to 10 carbon atoms.

The divalent aliphatic cyclic group represented by L is preferably acycloalkylene group having 3 to 20 carbon atoms and more preferably acycloalkylene group having 3 to 15 carbon atoms.

L is preferably —(C═O)O— or —O(C═O)— and more preferably —(C═O)O—.

From the viewpoint of surface uneven distribution advantageous foradhesiveness and from the viewpoint of radical polymerization, it ispreferable that the repeating unit represented by Formula (I) is arepeating unit represented by Formula (III).

In Formula (III), R¹ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms, ma and na each independently represent an integerof 1 to 20, and X represents a hydrogen atom or a fluorine atom.

In Formula (III), R¹ is the same as R¹ in Formula (I), and thepreferable range thereof is also the same.

In Formula (III), ma and na represent an integer of 1 to 20.

From the viewpoint of surface uneven distribution advantageous foradhesiveness and from the viewpoint of ease of material availability andproduction, ma in Formula (III) is preferably an integer of 1 to 8 andmore preferably an integer of 1 to 5. In addition, na is preferably aninteger of 1 to 15, more preferably an integer of 1 to 12, even morepreferably an integer of 2 to 10, and most preferably an integer of 5 to7.

In Formula (III), X represents a hydrogen atom or a fluorine atom andpreferably represents a fluorine atom.

The repeating unit represented by Formula (I) or (III) can be obtainedby polymerizing a monomer, and examples of preferable monomers include2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3,3-tetrafluoropropyl(meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate,2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl(meth)acrylate, 2-(perfluorodecyl)ethyl (meth)acrylate,2-(perfluoro-3-methylbutyl)ethyl (meth)acrylate,2-(perfluoro-5-methylhexyl)ethyl (meth)acrylate,2-(perfluoro-7-methyloctyl)ethyl (meth)acrylate, 1H,1H,3H-tetrafluoropropyl (meth)acrylate, 1H, 1H,5H-octafluoropentyl(meth)acrylate, 1H, 1H,7H-dodecafluoroheptyl (meth)acrylate,1H,1H,9H-hexadecafluorononyl (meth)acrylate,1H-1-(trifluoromethyl)trifluoroethyl (meth)acrylate,1H,1H,3H-hexafluorobutyl (meth)acrylate,3-perfluorobutyl-2-hydroxypropyl (meth)acrylate,3-perfluorohexyl-2-hydroxypropyl (meth)acrylate,3-perfluorooctyl-2-hydroxypropyl (meth)acrylate,3-(perfluoro-3-methylbutyl)-2-hydroxypropyl (meth)acrylate,3-(perfluoro-5-methylhexyl)-2-hydroxypropyl (meth)acrylate, and3-(perfluoro-7-methyloctyl)-2-hydroxypropyl (meth)acrylate.

As described above, in Formula (I), R² is preferably an alkyl grouphaving 1 to 20 carbon atoms and having at least one fluorine atom as asubstituent, and as another aspect, in Formula (I), R² has a repeatingunit including a siloxane bond represented by—Si(R^(a3))(R^(a4))O-(polysiloxane structure). In this case, as thecopolymer (a), a graft copolymer in which the polysiloxane structure isintroduced into the side chain is preferable. A compound having asiloxane bond for obtaining this graft copolymer is more preferably acompound represented by Formula (IV).

R^(a3) and R^(a4) each independently represent an alkyl group, ahaloalkyl group, or an aryl group. As the alkyl group, an alkyl grouphaving 1 to 10 carbon atoms is preferable. Examples thereof include amethyl group, an ethyl group, and a hexyl group. As the haloalkyl group,a fluorinated alkyl group having 1 to 10 carbon atoms is preferable.Examples thereof include a trifluoromethyl group, and a pentafluoroethylgroup. As the aryl group, an aryl group having 6 to 20 carbon atoms ispreferable. Examples thereof include a phenyl group, and a naphthylgroup. Among these, R^(a3) and R^(a4) preferably represent a methylgroup, a trifluoromethyl group, or a phenyl group and particularlypreferably represent a methyl group.

R^(a1) represents a hydrogen atom or an alkyl group having 1 to 20carbon atoms. R^(a5) preferably represents an alkyl group having 1 to 12carbon atoms and more preferably represents an alkyl group having 1 to 4carbon atoms.

nn is preferably 10 to 1000, more preferably 20 to 500, and even morepreferably 30 to 200.

In Formula (IV), nn R^(a3) 's may be the same as or different from eachother and nn R^(a4)'s may be the same as or different from each other.

As the compound having a siloxane bond for graft copolymerization, apolysiloxane macromonomer containing a (meth)acryloyl group at oneterminal (for example, SILAPLANE 0721, and SILAPLANE 0725 (all tradenames, manufactured by JNC Corporation), AK-5, AK-30, and AK-32 (alltrade names, manufactured by Toagosei Co., Ltd.), KF-100T, X-22-169AS,KF-102, X-22-37011E, X-22-164B, X-22-164C, X-22-5002, X-22-173B,X-22-174D, X-22-167B, and X-22-161AS (all trade names, manufactured byShin-Etsu Chemical Co., Ltd.)) may be exemplified.

Next, Formula (II) will be described.

The copolymer (a) also has a repeating unit represented by Formula (II).The repeating unit represented by Formula (II) has a strong interactionwith a hydroxyl group. That is, in a case where a coating solution of acomposition including the copolymer (a) (composition for forming afunctional film) is applied to a substrate (substrate film) and then anadhesive layer having a hydroxyl group is provided on the coatingsolution surface, a part or all of the repeating unit represented byFormula (II) interacts with the hydroxyl group so that the copolymer (a)is diffused and adsorbed into the interface of the adhesive layer havinga hydroxyl group and the inner side of the adhesive layer.

Accordingly, after the functional film and the adhesive layer are incontact with each other, the copolymer (a) having the repeating unitrepresented by Formula (II), which is added to the coating solution, ispresent at the functional film, the adhesive layer, and the interfacebetween both layers in the form of a copolymer having the chemicalstructure of Formula (II) as it is or a derivative (crosslinked reactionproduct) having a structure in which the repeating unit represented byFormula (II) reacts with the hydroxyl group of the adhesive layer.

As described above, since the copolymer (a) having the repeating unitrepresented by Formula (II) interacts with the adhesive layer,regardless of the ration between the adhesive layer and/or the copolymer(a) present in the functional film, the adhesiveness between thefunctional film including the copolymer (a) and the adhesive layer canbe enhanced.

In Formula (II), R¹⁰ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms, R¹¹ and R¹² each independently represent ahydrogen atom, a substituted or unsubstituted aliphatic hydrocarbongroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heteroaryl group, and R¹¹ and R¹² may be linked to eachother. X¹ represents a divalent linking group.

In Formula (II), R¹⁰ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms, preferably represents a hydrogen atom or an alkylgroup having 1 to 10 carbon atoms, more preferably represents a hydrogenatom or an alkyl group having 1 to 4 carbon atoms, and most preferablyrepresents a hydrogen atom or a methyl group.

The substituted or unsubstituted aliphatic hydrocarbon group representedby each of R¹¹ and R¹² in Formula (II) includes a substituted orunsubstituted alkyl group, a substituted or unsubstituted alkenyl group,and a substituted or unsubstituted alkynyl group. Specific examples ofthe alkyl group include linear, branched, or cyclic alkyl groups such asa methyl group, an ethyl group, a propyl group, a butyl group, a pentylgroup, a hexyl group, a heptyl group, an octyl group, a nonyl group, adecyl group, an undecyl group, a dodecyl group, a tridecyl group, ahexadecyl group, an octadecyl group, an eicosyl group, an isopropylgroup, an isobutyl group, a sec-butyl group, a tert-butyl group, anisopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexylgroup, a 2-methylhexyl group, a cyclopentyl group, a cyclohexyl group, a1-adamantyl group, and a 2-norbomyl group.

Specific examples of the alkenyl group include linear, branched, orcyclic alkyl alkenyl groups such as a vinyl group, a 1-propenyl group, a1-butenyl group, a 1-methyl-1-propenyl group, a 1-cyclopentenyl group,and a 1-cyclohexenyl group.

Specific examples of the alkynyl group include an ethynyl group, a1-propynyl group, a 1-butynyl group, and a 1-octynyl group.

Specific examples of the substituted or unsubstituted aryl grouprepresented by each of R¹¹ and R¹² include a phenyl group. Also, one inwhich two to four benzene rings form a fused ring, and one in which abenzene ring and an unsaturated five-membered ring form a fused ring maybe included. Specific examples thereof include a naphthyl group, ananthryl group, a phenanthryl group, an indenyl group, an acenaphthenylgroup, a fluorenyl group, and a pyrenyl group.

In addition, examples of the substituted or unsubstituted heteroarylgroup represented by each of R¹¹ and R¹² include one in which onehydrogen atom on a heteroaromatic ring containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygenatom and a sulfur atom is eliminated to form a heteroaryl group.Specific examples of the heteroaromatic ring containing one or morehetero atoms selected from the group consisting of a nitrogen atom, anoxygen atom and a sulfur atom include pyrrole, furan, thiophene,pyrazole, imidazole, triazole, oxazole, isoxazole, oxadiazole, thiazole,thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene,dibenzothiophene, indazole benzimidazole, anthranil, benzisoxazole,benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine,pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine,quinazoline, quinoxaline, naphthyridine, phenanthroline, and pteridine.

R¹¹ and R¹² may be linked to each other. In this case, it is preferablethat R¹¹ and R¹² each independently represent an alkyl group or an arylgroup, and these groups are linked to each other, and it is morepreferable that R¹¹ and R¹² each independently represent an alkyl groupand these groups are linked to each other.

The divalent linking group represented by X¹ preferably includes atleast one linking group selected from —(C═O)O—, —O(C═O)—, —(C═O)NH—,—O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O—, and —CH₂—, and the number ofcarbon atoms is preferably 7 or more.

R¹¹, R¹² and X¹ may be substituted by one or more substituents, ifpossible. As the substituent, a monovalent nonmetallic atomic groupexcluding a hydrogen atom can be exemplified and for example, thesubstituent is selected from the following substituent group Y.

Substituent group Y:

Halogen atom (—F, —Br, —Cl, —I), hydroxyl group, alkoxy group, aryloxygroup, mercapto group, alkyl thio group, aryl thio group, alkyl dithiogroup, aryl dithio group, amino group, N-alkyl amino group, N,N-dialkylamino group, N-aryl amino group, N,N-diaryl amino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxygroup, N-aryl carbamoyloxy group, N,N-dialkyl carbamoyloxy group,N,N-diaryl carbamoyloxy group, N-alkyl-N-aryl carbamoyloxy group, alkylsulfoxy group, aryl sulfoxy group, acyl thio group, acyl amino group,N-alkyl acyl amino group, N-aryl acyl amino group, ureido group,N′-alkyl ureido group, N′,N′-dialkyl ureido group, N′-aryl ureido group,N′,N′-diaryl ureido group, N′-alkyl-N′-aryl ureido group, N-alkyl ureidogroup, N-aryl ureido group, N′-alkyl-N-alkyl ureido group,N′-alkyl-N-aryl ureido group. N′,N′-dialkyl-N-alkyl ureido group.N′,N′-dialkyl-N-aryl ureido group, N′-aryl-N-alkyl ureido group,N′-aryl-N-aryl ureido group, N′,N′-diaryl-N-alkyl ureido group,N′,N′-diaryl-N-aryl ureido group, N′-alkyl-N′-aryl-N-alkyl ureido group,N′-alkyl-N′-aryl-N-aryl ureido group, alkoxy carbonyl amino group,aryloxy carbonyl amino group, N-alkyl-N-alkoxycarbonyl amino group,N-alkyl-N-aryloxy carbonyl amino group, N-aryl-N-alkoxycarbonyl aminogroup, N-aryl-N-aryloxycarbonyl amino group, formyl group, acyl group,carboxyl group and its conjugated basic group, alkoxy carbonyl group,aryloxy carbonyl group, carbamoyl group, N-alkyl carbamoyl group.N,N-dialkyl carbamoyl group, N-aryl carbamoyl group, N,N-diarylcarbamoyl group, N-alkyl-N-aryl carbamoyl group, alkyl sulfinyl group,aryl sulfinyl group, alkyl sulfonyl group, aryl sulfonyl group, sulfogroup (—SO₃H) and its conjugated basic group, alkoxy sulfonyl group,aryloxy sulfonyl group, sulfinamoyl group, N-alkyl sulfinamoyl group,N,N-dialkyl sulfinamoyl group, N-aryl sulfinamoyl group, N,N-diarylsulfinamoyl group, N-alkyl-N-aryl sulfinamoyl group, sulfamoyl group,N-alkyl sulfamoyl group. N,N-dialkyl sulfamoyl group, N-aryl sulfamoylgroup, N,N-diaryl sulfamoyl group, N-alkyl-N-aryl sulfamoyl group,N-acyl sulfamoyl group and its conjugated basic group. N-alkyl sulfonylsulfamoyl group (—SO₂NHSO₂(alkyl)) and its conjugated basic group,N-aryl sulfonyl sulfamoyl group (—SO₂NHSO₂(aryl)) and its conjugatedbasic group, N-alkyl sulfonyl carbamoyl group (—CONHSO₂(alkyl)) and itsconjugated basic group. N-aryl sulfonyl carbamoyl group (—CONHSO₂(aryl))and its conjugated basic group, alkoxy silyl group (—Si(Oalkyl)₃),aryloxy silyl group (—Si(Oaryl)₃), hydroxylyl group (—Si(OH)₃) and itsconjugated basic group, pohsphono group (—POH₂) and its conjugated basicgroup, dialkyl phosphono group (—PO₃(alkyl)₂), diaryl phosphono group(—PO₃(aryl)₂), alkyl aryl phosphono group (—PO₃(alkyl)(aryl)), monoalkylphosphono group (—PO₃H(alkyl)) and its conjugated basic group, monoarylphosphono group (—PO₃H(aryl)) and its conjugated basic group,phosphonoxy group (—OPO₃H₂) and its conjugated basic group, dialkylphosphonoxy group (—OPO₃(alkyl)₂), diaryl phosphonoxy group(—OPO₃(aryl)₂), alkyl aryl phosphonoxy group (—OPO₃(alkyl)(aryl)),monoalkyl phosphonoxy group (—OPO₃H(alkyl)) and its conjugated basicgroup, monoaryl phosphonoxy group (—OPO₃H(aryl)) and its conjugatedbasic group, cyano group, nitro group, aryl group, alkenyl group, andalkynyl group.

In addition, if possible, these substituents may be bonded to oneanother or to a substituted hydrocarbon group to form a ring.

It is preferable that R¹¹ and R¹² in Formula (II) each independentlyrepresent a hydrogen atom or an alkyl group or both represent an alkylgroup and bonded to each other to form a ring. It is more preferablethat R¹¹ and R¹² both represent a hydrogen atom or an alkyl group andbonded to each other to form a ring.

From the viewpoint of adhesiveness, it is preferable that the repeatingunit represented by Formula (II) is a repeating unit represented byFormula (V). Improvement of adhesiveness by the repeating unitrepresented by Formula (V) is presumed to be due to the effect ofbringing polarity closer to the adhesive layer having a hydroxyl group.

In Formula (V), R¹⁰ represents a hydrogen atom or an alkyl group having1 to 20 carbon atoms. R¹¹ and R¹² each independently represent ahydrogen atom, a substituted or unsubstituted aliphatic hydrocarbongroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heteroaryl group, and R¹¹ and R¹² may be linked to eachother. X¹¹ represents a divalent linking group comprising at least oneselected from the group consisting of —(C═O)O—, —O(C═O)—, —(C═O)NH—,—O—, —CO—, and —CH₂—. X¹² represents a divalent linking group includingat least one linking group selected from —(C═O)O—, —O(C═O)—, —(C═O)NH—,—O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂— and including atleast one substituted or unsubstituted aromatic ring. However, the totalnumber of carbon atoms of X¹¹ and X¹² is 7 or more.

X¹¹ in Formula (V) is preferably —(C═O)O—, —O(C═O)—, or —(C═O)NH— andmost preferably —(C═O)O—.

X¹² preferably contains 1 to 5 aromatic rings, more preferably contains2 to 4 aromatic rings, and most preferably contains 2 to 3 aromaticrings.

The preferable range of each of R¹⁰, R¹¹, and R¹² in Formula (V) is thesame as the preferable range of each of R¹⁰, R¹¹, and R¹² in Formula(II).

The repeating unit represented by Formula (II) or (V) is more preferablya repeating unit represented by Formula (VI).

In Formula (VI), X²¹ represents —(C═O)O—, or —(C═O)NH—. X²² represents adivalent linking group including at least one linking group selectedfrom —(C═O)O—, —O(C═O)—. —(C═O)NH—, —O—, —CO—, —NH—, —O(C═O)—NH—,—O(C═O)—O—, and —CH₂—, and X²² may include a substituted orunsubstituted aromatic ring.

The preferable range of each of R¹⁰, R¹¹, and R¹² in Formula (VI) is thesame as the preferable range of each of R¹⁰, R¹¹, and R¹² in Formula(II).

The repeating unit represented by Formula (II), (V) or (VI) can beobtained by polymerizing a monomer. Specific examples of preferablemonomers giving the repeating unit represented by Formula (II), (V) or(VI) are shown, but the present invention is not limited thereto.

In addition, the copolymer (a) in the present invention may haverepeating units (other repeating units) other than the repeating unitrepresented by Formula (I) and the repeating unit represented by Formula(II), if necessary.

As other kinds of monomers which give other repeating units, monomersdescribed in Polymer Handbook 2nd ed., J. Brandrup, Wiley Interscience(1975) Chapter 2, Pages 1 to 483 can be used. For example, compoundshaving one addition polymerizable unsaturated bond selected from acrylicacid, methacrylic acid, acrylic acid esters, methacrylic acid esters,acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinylesters, dialkyl itaconates, dialkyl esters or monoalkyl esters offumaric acid, and the like can be used.

Specific examples of monomers which give other repeating units includethe following monomers.

Acrylic Acid Esters:

methyl acrylate, ethyl acrylate, propyl acrylate, chloroethyl acrylate,2-hydroxyethyl acrylate, trimethylolpropane monoacrylate, benzylacrylate, methoxybenzyl acrylate, phenoxyethyl acrylate, furfurylacrylate, tetrahydrofurfuryl acrylate, 2-acryloyloxyethyl succinate,2-carboxyethyl acrylate, and the like;

Methacrylic Acid Esters:

methyl methacrylate, ethyl methacrylate, propyl methacrylate,chloroethyl methacrylate, 2-hydroxyethyl methacrylate,trimethylolpropane monomethacrylate, benzyl methacrylate, methoxybenzylmethacrylate, phenoxyethyl methacrylate, furfuryl methacrylate,tetrahydrofurfuryl methacrylate, ethylene glycol monoacetoacetatemonomethacrylate, 2-methacryloyloxyethyl phthalate,2-methacryloyloxyethyl succinate, 2-methacryloyloxyethylhexahydrophthalate, 2-carboxyethyl methacrylate, and the like:

Acrylamides:

acrylamide, N-alkyl acrylamide (as the alkyl group, an alkyl grouphaving 1 to 3 carbon atoms, for example, a methyl group, an ethyl group,or a propyl group), N,N-dialkyl acrylamide (as the alkyl group, an alkylgroup having 1 to 6 carbon atoms) N-hydroxyethyl-N-methylacrylamide,N-2-acetamidoethyl-N-acetylacrylamide, and the like;

Methacrylamides:

methacrylamide, N-alkyl methacrylamide (as the alkyl group, an alkylgroup having 1 to 3 carbon atoms, for example, a methyl group, an ethylgroup, or a propyl group), N, N-dialkyl methacrylamide (as the alkylgroup, an alkyl group having 1 to 6 carbon atoms).N-hydroxyethyl-N-methylmethacrylamide. N-2-acetamidoethyl-N-acetylmethacrylamide, and the like;

Allyl Compounds:

allyl esters (for example, allyl acetate, allyl caproate, allylcaprylate, allyl laurate, allyl palmitate, allyl stearate, allylbenzoate, allyl acetoacetate, and allyl lactate), allyloxyethanol, andthe like;

Vinyl Ethers:

alkyl vinyl ether (for example, hexyl vinyl ether, octyl vinyl ether,decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether,ethoxyethyl vinyl ether, chloroethyl vinyl ether,l-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether,hydroxyethyl vinyl ether, diethylene glycol vinyl ether,dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether,butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydro furfurylvinyl ether, and the like);

Vinyl Esters:

vinyl acetate, vinyl butyrate, vinyl isobutyrate, vinyltrimethylacetate, vinyl diethylacetate, vinyl valerate, vinyl caproate,vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinylbutoxyacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate, and the like.

Dialkyl Itaconates:

dimethyl itaconate, diethyl itaconate, dibutyl itaconate, and the like;

Dialkyl esters or monoalkyl esters of fumaric acid: dibutyl fumalate andthe like.

Examples of monomers which give other repeating units include crotonicacid, itaconic acid, acrylonitrile, methacrylonitrile, maleonitrile,styrene, 4-vinyl benzoic acid, styrene macromer (AS-6S manufactured byToagosei Co., Ltd.), and methyl methacrylate macromer (AA-6 manufacturedby Toagosei Co., Ltd.). In addition, it is also possible to convert thestructure of the polymer after polymerization by polymer reaction.

Further, it is preferable that the copolymer (a) has a thermallycrosslinking group. The thermally crosslinking group is a group thatcauses a crosslinking reaction by heating to conduct crosslinking, andspecific examples thereof include a carboxyl group, an oxazoline group,a hydroxyl group, an isocyanate group, a maleimide group, anacetoacetoxy group, an epoxy group, and amino group. It is preferablethat the copolymer (a) includes a repeating unit having a thermallycrosslinking group.

In a case where the copolymer (a) of the present invention is containedin a functional film, it is particularly preferable that the copolymeris thermally crosslinked with other compounds included in the functionalfilm, particularly, a styrene-based resin. Since the copolymer (a) andthe styrene-based resin respectively have thermally crosslinking groupsshowing reactivity with each other, the copolymer (a) can be immobilizedon the surface of the functional film and the functional film canexhibit higher adhesiveness with other layers, films, or other articles.

The content of the repeating unit represented by Formula (I) in thecopolymer (a) is preferably 5% to 95% by mass, more preferably 8% to 90%by mass, and even more preferably 10% to 85% by mass with respect to thetotal mass of the copolymer (a).

The content of the repeating unit represented by Formula (II) in thecopolymer (a) is preferably 0.5% to 80% by mass, more preferably 1% to70% by mass, and even more preferably 2% to 60% by mass with respect tothe total mass of the copolymer (a).

The content of the repeating unit having a thermally crosslinking groupin the copolymer (a) is preferably 0.5% to 60% by mass, more preferably1% to 50% by mass, and even more preferably 2% to 40% by mass withrespect to the total mass of the copolymer (a).

The weight-average molecular weight (Mw) of the copolymer of the presentinvention is preferably 1000 to 200000, more preferably 1800 to 150000,even more preferably 2000 to 150000, particularly preferably 2500 to140000, and highly preferably 20000 to 120000.

The number average molecular weight (Mn) of the copolymer of the presentinvention is preferably 500 to 160000, more preferably 600 to 120000,even more preferably 600 to 100000, particularly preferably 1000 to80000, and highly preferably 2000 to 60000.

The distribution (Mw/Mn) of the copolymer of the present invention ispreferably 1.00 to 18.00, more preferably 1.00 to 16.00, even morepreferably 1.00 to 14.00, particularly preferably 1.00 to 12.00, andhighly preferably 1.00 to 10.00.

The weight-average molecular weight and the number average molecularweight are values measured by gel permeation chromatography (GPC) underthe following conditions.

[Eluent] N-methyl-2-pyrrolidone (NMP)

[Apparatus name] EcoSEC HLC-8320GPC (manufactured by Tosoh Corporation)

[Column] TSKgel Super AWM-H (manufactured by manufactured by TosohCorporation)

[Column temperature] 40° C.

[Flow rate] 0.50 ml/min

The copolymer (a) can be synthesized by a known method.

Specific examples of the copolymer (a) will be shown below, but thepresent invention is not limited to these examples.

In a case where the copolymer (a) is contained in a functional film,from the viewpoint of enhancing the adhesion with the adhesive withoutimpairing the function of the functional film, the content of thecopolymer (a) is preferably 0.0001% to 40% by mass, more preferably0.001% to 20%, by mass, and even more preferably 0.005% to 10% by mass,assuming that the total solid content (all components excluding thesolvent) of the functional film is 100% by mass.

<Composition>

The present invention also relates to a composition containing thecopolymer (a) (also referred to as “composition (a)”). It is preferablethat the composition (a) contains a compound (monomer) having a reactivegroup in the molecule, such as a polymer resin, which will be describedlater, in addition to the copolymer (a).

<Functional Film>

Hereinafter, a functional film containing the copolymer (a) of thepresent invention will be described. It is preferable that thefunctional film containing the copolymer (a) is a functional film formedof the composition (a) containing the copolymer (a) (a composition forforming a functional film). More specifically, a functional film formedby applying the composition for forming a functional film on a substrateis preferable. The copolymer (a) may be a crosslinked reaction productin the functional film.

The functional film in the present invention may be any of a transparentfilm, an opaque film, and a colored film, but a transparent film ispreferable. In addition, the transparent film may have a transmittanceof 80% or more and a haze value of 5% or less. In addition, thefunctional film may be a film having a phase difference.

Specific examples of the functional film include a polarizer protectivefilm (a polarizing plate protective film), a low moisture permeablefilm, an optically anisotropic film, and an optically isotropic film.

Since the functional film is particularly excellent in adhesiveness witha resin having a hydroxyl group, other layers, films, or other articlesdirectly in contact with the functional film preferably includes a resinhaving a hydroxyl group. Examples of the resin having a hydroxyl groupinclude polyvinyl alcohol-based resins, polyvinyl butyral resins, andbisphenol A type epoxy resins.

(Configuration of Functional Film)

The functional film may be a single film or may have a laminatedstructure of two or more layers.

(Film Thickness)

The film thickness of the functional film in the present invention ispreferably 0.1 to 30 μm, more preferably 0.2 to 20 μm, and even morepreferably 0.4 to 10 m. By setting the film thickness to 0.1 μm or moreor more, it becomes possible to secure processing suitability anddurability in a case of lamination on a polarizer, and a film thicknessof 30 μm or less is preferable from the viewpoint of being capable ofreducing the thickness of a polarizing plate. In addition, in a casewhere the functional film is mounted on a liquid crystal display device,the effect of reducing light unevenness of the liquid crystal displaydevice due to environmental change and the effect of reducing warping ofthe liquid crystal panel due to temperature and humidity change can beexpected, and thus the film thickness is preferable.

(Equilibrium Moisture Absorptivity)

The equilibrium moisture absorptivity of the functional film ispreferably 2.0% by mass or less and more preferably 1.0% by mass or lessunder the conditions of a temperature of 25° C. and a relative humidityof 80% regardless of film thickness from the viewpoint of durability ina case of lamination on a polarizer. A case where the equilibriummoisture absorptivity is 2.0% by mass or less is preferable from theviewpoint of suppressing mixing of hydrophilic components to deterioratethe durability of a polarizer.

In the present specification, the equilibrium moisture absorptivity ofthe functional film can be measured using a sample whose film thicknessis increased if necessary. The equilibrium moisture absorptivity can bemeasured by humidity-conditioning a sample for 24 hours or longer, thenmeasuring a moisture content (g) by the Karl Fischer method with amoisture measuring instrument and a sample drying apparatus “CA-03” and“VA-05” {both manufactured by Mitsubishi Chemical Corporation}, anddividing the moisture content (g) by the sample mass (g).

(Other Materials Constituting Functional Film)

As other materials constituting the functional film of the presentinvention, in addition to the copolymer (a), a cured product derivedfrom a compound (monomer) having a reactive group in the molecule and/ora polymer resin can be suitably used.

(Cured Product Derived from Compound Having Reactive Group in Molecule)

The functional film preferably contains a cured product derived from acompound (monomer) having a reactive group in the molecule. The compoundhaving a reactive group in the molecule is referred to as “compound(b)”. The number of reactive groups in the molecule of the compound (b)is more preferably 2 or more and even more preferably 3 or more from theviewpoint that the compound can be three-dimensionally intertwined withcopolymer (a) and immobilized.

In addition, the reactive group is particularly preferably anethylenically unsaturated double bond-containing group.

Further, from the viewpoint of controlling peelability between thefunctional film and the substrate, as the compound (b), a compoundhaving an ethylenically unsaturated double bond-containing group and acyclic aliphatic hydrocarbon group is preferable.

<<Compound Having Group Having Ethylenically Unsaturated Double Bond andCyclic Aliphatic Hydrocarbon Group>>

The cyclic aliphatic hydrocarbon group is preferably a group derivedfrom an alicyclic compound having 7 or more carbon atoms, morepreferably a group derived from an alicyclic compound having 10 or morecarbon atoms, and even more preferably a group derived from an alicycliccompound having 12 or more carbon atoms.

The cyclic aliphatic hydrocarbon group is particularly preferably agroup derived from a polycyclic compound such as a bicyclic or tricycliccompound.

More preferable are center skeleton of a compound disclosed in claims ofJP2006-215096A, a center skeleton of a compound disclosed inJP2001-010999A, a skeleton of an adamantane derivative and the like.

Specific examples of the cyclic aliphatic hydrocarbon group include anorbornane group, a tricyclodecane group, a tetracyclododecane group, apentacyclopentadecane group, an adamantane group, and a diamantanegroup.

The cyclic aliphatic hydrocarbon group (including a linking group) ispreferably a group represented by any one of Formulae (A) to (E), morepreferably a group represented by Formula (A), (B) or (D), even morepreferably a group represented by Formula (A).

In Formula (A), L¹⁰ and L¹¹ each independently represent a single bondor a divalent or higher valent linking group. n represents an integer of1 to 3.

The cyclic aliphatic hydrocarbon group and an ethylenically unsaturateddouble bond-containing group are bonded through L¹⁰ and L¹¹.

In Formula (B), L²⁰ and L²¹ each independently represent a single bondor a divalent or higher valent linking group. n represents an integer of1 or 2.

The cyclic aliphatic hydrocarbon group and an ethylenically unsaturateddouble bond-containing group are bonded through L²⁰ and L²¹.

In Formula (C), L³⁰ and L³¹ each independently represent a single bondor a divalent or higher valent linking group. n represents an integer of1 or 2.

The cyclic aliphatic hydrocarbon group and an ethylenically unsaturateddouble bond-containing group are bonded through L³⁰ and L³¹.

In Formula (D), L⁴⁰ and L⁴¹ each independently represent a single bondor a divalent or higher valent linking group. L⁴² represents a hydrogenatom, a single bond, or a divalent or higher valent linking group.

The cyclic aliphatic hydrocarbon group and an ethylenically unsaturateddouble bond-containing group are bonded through L⁴⁰ and L⁴¹. In a casewhere L⁴² represents a single bond, or a divalent or higher valentlinking group, the cyclic aliphatic hydrocarbon group and anethylenically unsaturated double bond-containing group are bondedthrough L⁴².

In Formula (E), L⁵⁰ and L⁵¹ each independently represent a single bondor a divalent or higher valent linking group.

The cyclic aliphatic hydrocarbon group and an ethylenically unsaturateddouble bond-containing group are bonded through L⁵⁰ and L⁵¹.

In Formulae (A) to (E), the divalent or higher valent linking grouprepresented by L¹⁰, L¹¹, L²⁰, L²¹, L³⁰, L³¹, L⁴⁰, L⁴¹, L⁴², L⁵⁰, and L⁵¹includes an alkylene group having 1 to 6 carbon atoms, which may besubstituted, an amide group which may be substituted at the N-position,a carbamoyl group which may be substituted at the N-position, an estergroup, an oxycarbonyl group, an ether group, and a group formed bycombining two or more groups thereof.

The ethylenically unsaturated double bond-containing group includes apolymerizable functional group such as (meth)acryloyl group, vinylgroup, styryl group and allyl group, and among these, a (meth)acryloylgroup and —C(O)OCH═CH₂ are preferable. More preferably, the followingcompound containing two or more (meth)acryloyl groups in one moleculecan be used. Particularly preferably, the following compound containingthree or more (meth)acryloyl groups in one molecule can be used.

The compound having a cyclic aliphatic hydrocarbon group and containingtwo or more ethylenically unsaturated double bonds in the molecule isconstituted by bonding the cyclic aliphatic hydrocarbon group to anethylenically unsaturated double bond-containing group through a linkinggroup.

Such a compound can be easily synthesized, for example, by a one-step ortwo-step reaction of a polyol, such as diol or triol, having the cyclicaliphatic hydrocarbon group, with a carboxylic acid, a carboxylic acidderivative, an epoxy derivative, an isocyanate derivative, or the like,of a compound having a (meth)acryloyl group, a vinyl group, a styrylgroup, an allyl group, or the like.

Preferably, the above compound may be synthesized through the reactionwith a polyol having the cyclic aliphatic hydrocarbon group by using acompound such as (meth)acrylic acid, (meth)acryloyl chloride,(meth)acrylic anhydride and glycidyl (meth)acrylate, or a compounddescribed in WO2012/000316A (for example,1,1-bis(acryloyloxymethyl)ethyl isocyanate).

Preferable specific examples of the compound having an ethylenicallyunsaturated double bond-containing group and a cyclic aliphatichydrocarbon group are shown below, but the present invention is notlimited to these examples.

In a case where the functional film contains the compound (b) and acured product thereof, the content of the compound (b) and the curedproduct thereof is preferably 5% to 99.9% by mass and more preferably10% to 90% by mass, assuming that the total solid content (allcomponents excluding the solvent) of the functional film is 100 mass %.

(Polymerization Initiator)

In a case where the composition (a) (the composition for forming afunctional film) is a composition containing the compound having anethylenically unsaturated double bond-containing group in the moleculeand a cyclic aliphatic hydrocarbon group, it is preferable that thecomposition (a) includes a polymerization initiator. The polymerizationinitiator is preferably a photopolymerization initiator.

Examples of the photopolymerization initiator include acetophenones,benzoins, benzophenones, phosphine oxides, ketals, anthraquinones,thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds,disulfide compounds, fluoroamine compounds, aromatic sulfoniums, lophinedimers, onium salts, borate salts, active esters, active halogens,inorganic complexes, and coumarins. Specific examples, preferredaspects, commercially available products and the like of thephotopolymerization initiator are described in paragraphs [0133] to[0151] of JP2009-098658A, and these may be suitably used likewise in thepresent invention.

Various examples of the photopolymerization initiator are described alsoin “Latest UV Curing Technology” {Technical Information Institute Co.,Ltd.} (1991), p. 159 and “Ultraviolet Ray Curing System” written byKiyomi Kato (1989, published by United Engineering Center). pp. 65-148,and these are useful for the present invention.

Preferable examples of commercially available photoradicalpolymerization initiators of photocleavage type include “IRGACURE 651”,“IRGACURE 184”, “IRGACURE 819”, “IRGACURE 907”, “IRGACURE 1870” (a mixedinitiator of CGI-403/IRGACURE 184=7/3), “IRGACURE 500”, “IRGACURE 369”,“IRGACURE 1173”, “IRGACURE 2959”, “IRGACURE 4265”, “IRGACURE 4263”,“IRGACURE 127”. “OXE01”, and the like, manufactured by BASF (former CibaSpecialty Chemicals Inc.); “KAYACURE DETX-S”, “KAYACURE BP-100”,“KAYACURE BDMK”, “KAYACURE CTX”, “KAYACURE BMS”, “KAYACURE 2-EAQ”,“KAYACURE ABQ”, “KAYACURE CPTX”, “KAYACURE EPD”, “KAYACURE ITX”,“KAYACURE QTX”, “KAYACURE BTC”, “KAYACURE MCA”, and the like,manufactured by Nippon Kayaku Co., Ltd.; “ESACURE (KIP100F, KB1, EB3,BP, X33, KTO46, KT37, KIP150, and TZT)”, and the like, manufactured bySartomer Company Inc.; and a combination thereof.

In a case where the composition (a) (the composition for forming afunctional film) is a composition containing the compound having anethylenically unsaturated double bond-containing group in the moleculeand a cyclic aliphatic hydrocarbon group, it is preferable that thecontent of the photopolymerization initiator in the composition ispreferably 0.5% to 8% by mass and more preferably 1% to 5% by mass withrespect to the total solid content in the composition (a) for the reasonthat the content is set to polymerize a polymerizable compound includedin the composition (a) and prevent an excessive increase of theinitiation site.

(Polymer Resin)

The functional film may include a polymer resin (hereinafter, alsoreferred to as “resin (d)”), in addition to the copolymer (a) and/or thecrosslinked reaction product derived from the copolymer. From theviewpoint of improving brittleness resistance and modulus of elasticity,it is preferable that the resin includes, for example, a polar structurecapable of strengthening the interaction between the polymer molecules.Specific examples thereof include aromatic vinyl-based resin (preferablystyrene-based resin), cellulose-based resin (cellulose acylate resin,cellulose ether resin, or the like), cyclic olefin-based resin,polyester-based resin, polycarbonate-based resin, vinyl-based resinother than aromatic vinyl-based resin, polyimide-based resin, andpolyarylate-based resin, and aromatic vinyl-based resin and cyclicolefin resin are preferable from the viewpoint of hygroscopicity andmoisture permeability.

The aromatic vinyl-based resin is a vinyl-based resin including at leastone aromatic ring, and examples thereof include styrene-based resin,divinylbenzene-based resin, 1,1-diphenyl styrene-based resin,vinylnaphthalene-based resin, vinylanthracene-based resin, N,N-diethyl-p-aminoethylstyrene-based resin, and vinylpyridine-basedresin, and as the copolymerization component, a vinylpyridine unit, avinylpyrrolidone unit, a maleic acid anhydride unit, and the like may beappropriately included. Among the aromatic vinyl-based resins, from theviewpoint of controlling the photoelastic coefficient andhygroscopicity, it is preferable that the functional film includes astyrene-based resin.

One of these resins (d) may be used alone, or two or more thereof may beused in combination.

<<Styrene-Based Resin>>

As an example of the styrene-based resin, a resin including 50% by massor more of a repeating unit derived from a styrene-based monomer isexemplified. Here, the styrene-based monomer means a monomer having astyrene skeleton in its structure.

Specific examples of the styrene-based monomer include styrene or aderivative thereof. Here, the styrene derivative is a compound preparedby bonding styrene with another group, and examples thereof includealkylstyrene such as o-methylstyrene, m-methylstyrene, p-methylstyrene,2,4-dimethylstyrene, o-ethylstyrene, or p-ethylstyrene, and substitutedstyrene having a hydroxyl group, an alkoxy group, a carboxyl group, or ahalogen introduced into the benzene nucleus of styrene, such ashydroxystyrene, tert-butoxystyrene, vinyl benzoic acid, o-chlorostyreneand p-chlorostyrene.

The styrene-based resin may be a homopolymer of styrene or a derivativethereof, and in addition to this, a copolymer obtained by copolymerizinga styrene-based monomer component with another monomer component is alsoincluded. Examples of the copolymerizable monomer include

unsaturated carboxylic acid alkyl ester monomers including alkylmethacrylates such as methyl methacrylate, cyclohexyl methacrylate,methylphenyl methacrylate, and isopropyl methacrylate; and alkylacrylates such as methyl acrylate, ethyl acrylate, butyl acrylate,2-ethylhexyl acrylate, and cyclohexyl acrylate,

unsaturated carboxylic acid monomers such as such as methacrylic acid,acrylic acid, itaconic acid, maleic acid, fumaric acid, and cinnamicacid,

unsaturated dicarboxylic acid anhydride monomers as anhydrides of maleicacid, itaconic acid, ethylmaleic acid, methyl itaconic acid,chloromaleic acid, and the like,

unsaturated nitrile monomers such as acrylonitrile, andmethacrylonitrile, and

conjugated dienes such as 1,3-butadiene, 2-methyl-1,3-butadiene(isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and1,3-hexadiene, and two or more of these can be copolymerized.

The styrene-based resin is preferably a copolymer of styrene or astyrene derivative and at least one monomer selected from acrylonitrile,maleic acid anhydride, methyl methacrylate and 1,3-butadiene.

The polystyrene-based resin is not particularly limited and examplesthereof include a homopolymer of a styrene-based monomer such as generalpurpose polystyrene (GPPS) which is a homopolymer of styrene; acopolymer constituted only of two or more kinds of styrene-basedmonomers as a monomer component; a styrene-diene-based copolymer; acopolymer such as a styrene-polymerizable unsaturated carboxylic acidester-based copolymer; a mixture of polystyrene and synthetic rubber(for example, polybutadiene, polyisoprene, or the like); high impactpolystyrene (HIPS) such as polystyrene obtained by graft-polymerizingstyrene to synthetic rubber; a polystyrene obtained by dispersing arubbery elastomer in a continuous phase of a polymer containing astyrene-based monomer (for example, a copolymer of a styrene-basedmonomer and a (meth)acrylate ester-based monomer) and graft-polymerizingthe copolymer with the rubbery elastomer (also referred to as graft typehigh impact polystyrene, “graft HIPS”); and a styrene-based elastomer.

In addition, the polystyrene-based resin is not particularly limited andmay be hydrogenated. That is, the polystyrene-based resin may be apolystyrene-based resin to which hydrogen is added (hydrogenatedpolystyrene-based resin). Although the hydrogenated polystyrene-basedresin is not particularly limited, the hydrogenated polystyrene-basedresin is preferably a hydrogenated styrene-diene-based copolymer such asa hydrogenated styrene-butadiene-styrene block copolymer (SEBS) orhydrogenated styrene-isoprene-styrene block copolymer (SEPS) which is aresin obtained by adding hydrogen to SBS or SIS. Only one of thesehydrogenated polystyrene-based resins may be used, or two or morethereof may be used.

In addition, the polystyrene-based resin is not particularly limited anda polar group may be introduced thereinto. That is, thepolystyrene-based resin may be a polystyrene-based resin with a polargroup introduced therein (modified polystyrene-based resin). Themodified polystyrene-based resin includes a hydrogenatedpolystyrene-based resin with a polar group introduced therein.

The modified polystyrene-based resin is a polystyrene-based resin havinga polystyrene-based resin as a main chain skeleton and having a polargroup introduced therein. The polar group is not particularly limitedand examples thereof include an acid anhydride group, a carboxylic acidgroup, a carboxylic acid ester group, a carboxylic acid chloride group,a carboxylic acid amide group, a carboxylate group, a sulfonic acidgroup, a sulfonic acid ester group, a sulfonic acid chloride group, asulfonic acid amide group, a sulfonate group, an isocyanate group, anepoxy group, an amino group, an imide group, an oxazoline group, and ahydroxyl group. Among these, an acid anhydride group, a carboxylic acidgroup, a carboxylic acid ester group, and an epoxy group are preferableand a maleic acid anhydride group and an epoxy group are morepreferable. Only one of these polar groups may be used, or two or morethereof may be used. Since the modified polystyrene-based resin has apolar group having high affinity or reactable with the polyester-basedresin and is compatible with the polystyrene-based resin, theadhesiveness with a layer having a polyester-based resin as a maincomponent (for example, a surface layer or a layer B) or a layer havinga polystyrene-based resin as a main component (for example, anotherlayer A) at room temperature is increased. Only one of these polargroups may be used, or two or more thereof may be used.

The modified polystyrene-based resin is not particularly limited and amodified product of a hydrogenated styrene-butadiene-styrene blockcopolymer (SEBS) and a modified product of a hydrogenatedstyrene-propylene-styrene block copolymer (SEPS) are preferable. Thatis, although the modified polystyrene-based resin is not particularlylimited, acid anhydride modified SEBS, acid anhydride modified SEPS,epoxy modified SEBS, and epoxy modified SEPS are preferable, and maleicacid anhydride modified SEBS, maleic acid anhydride modified SEPS, epoxymodified SEBS, and epoxy modified SEPS are more preferable. Only one ofthese modified polystyrene-based resins may be used, or two or morethereof may be used.

As the styrene-based resin that can be suitably used in the presentinvention, for the reason of high heat resistance, polystyrene, astyrene/acrylonitrile copolymer, a styrene/methacrylic acid copolymer,and a styrene/maleic acid anhydride copolymer may be used.

Since a styrene/acrylonitrile copolymer, a styrene/methacrylic acidcopolymer, and a styrene/maleic acid anhydride copolymer exhibit highcompatibility with an acrylic resin, these copolymers are preferablefrom the viewpoint of obtaining a film which has high transparency andnot causing phase separation during use without lowering transparency.From this viewpoint, these copolymers are preferable particularly in acase where a polymer containing methyl methacrylate as a monomercomponent is used as an acrylic resin.

In a case of a styrene-acrylonitrile copolymer, the copolymer ratio ofacrylonitrile in the copolymer is preferably 1% to 40% by mass. A morepreferable range is 1% to 30% by mass and a particularly preferablerange is 1% to 25% by mass. A case where the copolymer ratio ofacrylonitrile in the copolymer is 1% by mass to 40% by mass ispreferable since the transparency is excellent.

In a case of a styrene-methacrylic acid copolymer, the copolymer ratioof methacrylic acid in the copolymer is preferably 0.1% to 50% by mass.A more preferable range is 0.1% to 40% by mass and a particularlypreferable range is 0.1% to 30% by mass. In a case where the copolymerratio of methacrylic acid in the copolymer is 0.1% by mass or more, theheat resistance is excellent and in a case where the ratio is in a rangeof 50% by mass or less, the transparency is excellent. Thus, thiscopolymer ratio range is preferable.

In a case of a styrene/maleic acid anhydride copolymer, the copolymerratio of maleic acid anhydride in the copolymer is preferably 0.1% to50% by mass. A more preferable range is 0.1% to 40% by mass and aparticularly preferable range is 0.1% to 30% by mass. In a case wherethe copolymer ratio of maleic acid anhydride in the copolymer is 0.1% bymass or more, the heat resistance is excellent and in a case where theratio is in a range of 50% by mass or less, the transparency isexcellent. Thus, this copolymer ratio range is preferable.

Among these, from the viewpoint of heat resistance, polystyrene, astyrene-methacrylic acid copolymer, and a styrene-maleic acid anhydridecopolymer are particularly preferable.

In addition, from the viewpoint of the adhesiveness between thefunctional film and other layers, films, or other articles, the mostsuitably used styrene-based resin is a styrene-based resin having athermally crosslinking group, and the styrene-based resin preferablycontains a repeating unit having a thermally crosslinking group. Thethermally crosslinking group is the same as the thermally crosslinkinggroup described in the above-described copolymer (a). In a case wherethe styrene-based resin has a thermally crosslinking group and thecopolymer (a) has a thermally crosslinking group, the copolymer (a) canbe immobilized on the surface of the functional film and higheradhesiveness can be exhibited. In this case, since it is possible toimmobilize the copolymer (a) on the surface of the functional film byreacting the thermally crosslinking group by heating, theabove-described process in which a compound (monomer) having a reactivegroup in the molecule is incorporated and the monomer is cured byionizing radiation irradiation with ultraviolet rays or the like so asto immobilize the copolymer (a) on the surface of the functional film isnot required and thus this case is preferable.

Hereinafter, specific examples of the styrene-based resin having athermally crosslinking group are listed, but the present invention isnot limited to these examples.

One styrene-based resin may be used alone or a plurality of kinds ofstyrene-based resins having different repeating unit compositions,molecular weights, and the like may be used in combination.

The styrene-based resin can be obtained by a known anion, bulk,suspension, emulsion or solution polymerization method. In addition, inthe styrene-based resin, the unsaturated double bond of the benzene ringof the conjugated diene or the styrene-based monomer may behydrogenated. The hydrogenation rate can be measured by a nuclearmagnetic resonance apparatus (NMR).

<<Cyclic Olefin-Based Resin>>

In a case where a cyclic olefin-based resin is used as a materialconstituting the functional film, for example, a thermoplastic resinhaving a unit of a monomer constituted of a cyclic olefin such asnorbornene or polycyclic norbornene-based monomer may be used and isalso referred to as a thermoplastic cyclic olefin-based resin. Thethermoplastic cyclic olefin-based resin may be a ring-opened polymer ofthe cyclic olefin or a hydrogenated product of a ring-opened copolymerusing two or more cyclic olefins and may be an addition polymer of acyclic olefin and a chain olefin and an aromatic compound having apolymerizable double bond such as a vinyl group. The cyclic olefin-basedresin may have a polar group introduced therein.

In a case where a copolymer of a cyclic olefin and a chain olefin and/oran aromatic compound having a vinyl group is used as the material forthe functional film, as the chain olefin, ethylene, propylene, and thelike may be used, and as the aromatic compound having a vinyl group,styrene, α-methylstyrene, nuclear alkyl-substituted styrene, and thelike may be used. In such a copolymer, the unit of the monomerconstituted of the cyclic olefin is preferably 50% by mol or less, andmore preferably about 15% to 50% by mol. Particularly, a ternarycopolymer of a cyclic olefin, a chain olefin, and an aromatic compoundhaving a vinyl group is used as the material for the functional film,the unit of the monomer constituted of the cyclic olefin can be reducedto a relatively small amount as described above. In the ternarycopolymer, the unit of the monomer constituted of the chain olefin istypically 5% to 80% by mol, and the unit of the monomer constituted ofthe aromatic compound having a vinyl group is typically 5% to 80% bymol.

As the cyclic olefin-based resin, any suitable commercially availableproduct can be used, and examples thereof include “TOPAS” manufacturedby TOPAS ADVANCED POLYMERS GmbH in Germany and available fromPolyplastics Co. Ltd. in Japan, “ARTON” available from JSR Corporation,“ZEONOR” and “ZEONEX” available from Zeon Corporation, and “APEL”available from Mitsui Chemicals Inc. (all trade names).

<<Cellulose Acylate Resin>>

In a case where a cellulose acylate resin is used as a materialconstituting the functional film, for example, cellulose acetate,cellulose acetate propionate, cellulose propionate, cellulose acetatebutyrate, cellulose acetate propionate butyrate, cellulose acetatebenzoate, and the like may be used. Among these, cellulose acetate, andcellulose acetate propionate are preferable.

<<Polycarbonate-Based Resin>>

In a case where a polycarbonate-based resin is used as a materialconstituting the functional film, for example, polycarbonate, apolycarbonate containing a structural unit in which bisphenol A isfluorene-modified, a polycarbonate containing a structural unit in whichbisphenol A is modified with 1,3-cyclohexylidene, and the like may beused.

<<Vinyl-Based Resin Other than Aromatic Vinyl-Based Resin>>

In a case where a vinyl-based resin other than the aromatic vinyl-basedresin is used as a material constituting the functional film, forexample, polyethylene, polypropylene, polyvinylidene chloride, polyvinylalcohol, and the like may be used.

(Weight-Average Molecular Weight of Resin (d))

The weight-average molecular weight (Mw) of the resin (d) is notparticularly limited and is preferably 5,000 to 800,000, more preferably100,000 to 600,000, and even more preferably 120,000) to 400,000.

The weight-average molecular weight of the resin (d) is obtained bymeasuring weight-average molecular weight (Mw) in terms of standardpolystyrene and molecular weight distribution (Mw/Mn) under thefollowing conditions. Mn is number average molecular weight in terms ofstandard polystyrene.

GPC: gel permeation chromatograph apparatus (HLC-8220GPC, manufacturedby Tosoh Corporation, column; guard columns HXL-H, TSK gel G7000HXL, twocolumns of TSK gel GMHXL, TSK gel G2000HXL, manufactured by TosohCorporation, sequentially link together, eluent; tetrahydrofuran, flowrate; 1 mL/min, sample concentration; 0.7% to 0.8% by mass, sampleinjection amount; 70 μL, measurement temperature; 40° C., detector;differential refractometer (RI) meter (40° C.), standard substance; TSKstandard polystyrene manufactured by Tosoh Corporation)

In a case where the functional film contains the resin (d), one resin(d) may be contained or two or more resins (d) may be used. In addition,in a case where the functional film is formed of a plurality of layers,the resins (d) included in each layer may be different from each other.

(Content of Resin (d) in Functional Film)

The content of the resin (d) in the functional film is preferably 5% to99.99% by mass and more preferably 10% to 99.9% by mass, assuming thatthe total solid content (all components excluding the solvent) of thefunctional film is 100% by mass.

(Solvent)

The composition for forming a functional film may contain a solvent. Thesolvent may be appropriately selected from the viewpoint of beingcapable of dissolving or dispersing the material for forming thefunctional film, easily forming a uniform surface in a coating step anda drying step, securing liquid preservability, having a suitablesaturated vapor pressure, and the like. Examples of such an organicsolvent include dibutyl ether, dimethoxyethane, diethoxyethane,propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane,tetrahydrofuran, anisole, phenetole, dimethyl carbonate, methyl ethylcarbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK),diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone,cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate,pentyl formate, methyl acetate, ethyl acetate, propyl acetate, methylpropionate, ethyl propionate, γ-butyrolactone, methyl 2-methoxyacetate,methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate,2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol,1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methylacetoacetate, ethyl acetoacetate, methyl alcohol, ethyl alcohol,isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutylacetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-heptanone,2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropylether, ethylene glycol butyl ether, propylene glycol methyl ether, ethylcarbitol, butyl carbitol, hexane, heptane, octane, cyclohexane,methylcyclohexane, ethylcyclohexane, benzene, toluene, and xylene. Oneof these solvents may be used alone, or two or more thereof may be usedin combination.

Among the solvents, it is preferable to use at least one of dimethylcarbonate, methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, or acetone, it is more preferable to use any of dimethylcarbonate and methyl acetate, and it is particularly preferable to usemethyl acetate.

The solvent is used such that the concentration of the solid content ofthe composition for forming a functional film is preferably in a rangeof 5% to 80% by mass, more preferably in a range of 10% to 75% by mass,and even more preferably in a range of 15% to 70% by mass.

(Additive)

In the functional film, known additives can be adequately mixed. Forexample, in a case where the functional film is used as a polarizingplate protective film, as known additives, a low molecular weightplasticizer, a leveling agent, an oligomer-based additive, apolyester-based additive, a retardation control agent, a matting agent,an ultraviolet absorber, a deterioration inhibitor, a peeling promoter,an infrared absorber, an antioxidant, a filler, a compatibilizer, andthe like may be used.

<Polyester-Based Additive>

In a case where the functional film is applied and formed on a substrateincluding a polyester resin, the adhesion between the functional filmand the substrate can be improved by incorporating a polyester-basedadditive into the functional film. Although the details of the reasonare not apparent, it is considered that since the polyester-basedadditive is similar in hydrophilic and hydrophobic properties andmolecular structure to the polyester resin contained in the substrate,the interaction therebetween occurs and adhesion is improved. Inaddition, in a case where the functional film includes theabove-described resin (d), it is considered that by making the additivebe similar in hydrophilic and hydrophobic properties and structure tothe resin (d), the additive is compatible with the resin (d) and thusthe transparency of functional film can be maintained. For example, in acase where the resin (d) included in the functional film is apolystyrene-based resin, it is considered that the structure of thepolyester-based additive secures compatibility with thepolystyrene-based resin in that the ester structure interacts with thepolyester resin in the substrate and has an aromatic ring, and as aresult, the adhesion between the functional film and the substrate filmis improved.

The polyester-based additive can be obtained by a known method such as adehydration condensation reaction of a polybasic acid and a polyhydricalcohol, or addition and dehydration condensation reaction ofdianhydride with a polyhydric alcohol, and is preferably a polycondensedester formed from a dibasic acid and a diol.

The weight-average molecular weight (Mw) of the polyester-based additiveis preferably 500 to 50,000, more preferably 750 to 40000, and even morepreferably 2000 to 30000.

A case where the weight-average molecular weight (Mw) of thepolyester-based additive is 500 or more is preferable from the viewpointof brittleness and moisture-heat resistance, and a case where theweight-average molecular weight is 50,000 or less is preferable from theviewpoint of compatibility with resin.

The weight-average molecular weight (Mw) of the polyester-based additivecan be measured by the same method as in the above description of theresin (d).

As the dibasic acid constituting the polyester-based additive, adicarboxylic acid can be preferably used.

Examples of the dicarboxylic acid include aliphatic dicarboxylic acidsand aromatic dicarboxylic acids, and an aromatic dicarboxylic acid, or amixture of an aromatic dicarboxylic acid and an aliphatic dicarboxylicacid can be preferably used.

Among the aromatic dicarboxylic acids, an aromatic dicarboxylic acidhaving 8 to 20 carbon atoms is preferable, and an aromatic dicarboxylicacid having 8 to 14 carbon atoms is more preferable. Specifically, atleast one selected from phthalic acid, isophthalic acid, andterephthalic acid is preferable.

Among the aliphatic dicarboxylic acids, an aliphatic dicarboxylic acidhaving 3 to 8 carbon atoms is preferable, and an aliphatic dicarboxylicacid having 4 to 6 carbon atoms is more preferable. Specifically, atleast one selected from succinic acid, maleic acid, adipic acid, andglutaric acid is preferable and at least one selected from succinic acidand adipic acid is more preferable.

Examples of the diol constituting the polyester-based additive includealiphatic diols and aromatic diols, and aliphatic diols are particularlypreferable.

Among the aliphatic diols, an aliphatic diol having 2 to 4 carbon atomsis preferable and an aliphatic diol having 2 or 3 carbon atoms is morepreferable.

Examples of the aliphatic diol include ethylene glycol, diethyleneglycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol,and 1,4-butylene glycol, and these may be used alone or in combinationof two or more thereof.

It is particularly preferable that the polyester-based additive is acompound obtained by condensing at least one selected from phthalicacid, isophthalic acid, and terephthalic acid and an aliphatic diol.

The terminal of the polyester-based additive may be blocked withreacting with a monocarboxylic acid. As the example of themonocarboxylic acid used in blocking, an aliphatic monocarboxylic acidis preferable, acetic acid, propionic acid, butanoic acid, benzoic acidand derivatives thereof are preferable, acetic acid or propionic acid ismore preferable, and acetic acid is most preferable.

Examples of commercially available polyester-based compounds includeester-based resin polyesters (for example, LP050, TP290, LP035, LP033.TP217, and TP220) manufactured by Nippon Synthetic Chemical IndustryCo., Ltd., and ester-based resins VYLON (VYLON 245, VYLON GK 890, VYLON103, VYLON 200, VYLON 550 GK 880) manufactured by Toyobo Co. Ltd.

The content of the polyester-based additive in the functional film ispreferably 0.1% by mass or more, more preferably 0.5% by mass or more,and even more preferably 1% by mass or more with respect to the totalmass of the functional film. In addition, the content of thepolyester-based additive of the functional film is preferably 25% bymass or less, more preferably 20% by mass or less, and even morepreferably 15% by mass or less with respect to the total mass of thefunctional film. The above range is preferable from the viewpoint ofobtaining appropriate adhesiveness.

(Matting Agent)

Fine particles may be added to the functional film surface for impartingto lubricity and preventing blocking. As fine particles, silica (silicondioxide, SiO₂) of which the surface is coated with a hydrophobic groupand which has a morphology of secondary particles is preferably used.Along with silica or in place of silica, other fine particles oftitanium dioxide, aluminium oxide, zirconium oxide, calcium carbonate,talc, clay, calcined kaolin, calcined calcium silicate, hydrated calciumsilicate, aluminium silicate, magnesium silicate, calcium phosphate, andthe like may also be used as fine particles. Examples of commercialproducts of such fine particles include trade names of R972 and NX90S(both manufactured by Nippon Aerosil Co., Ltd.).

The fine particles function as a so-called matting agent. Addition ofsuch fine particles forms fine unevenness on the film surface, and dueto the unevenness, the films do not stick to each other even in a casewhere the films are overlapped, and the lubricity between the films canbe secured. At this time, in a case where the number per mm² of the fineunevenness formed by fine particles protruding from the film surface andhaving a height of 30 nm or more is 104/mm² or more, the effect ofimproving the lubricity and blocking resistance is particularly great.

<Preparation of Functional Film>

The functional film can be prepared by a method of forming a coatinglayer on a substrate film by a known coating method, or a solution filmforming method, but a coating method is particularly preferably used.

The functional film can be formed on a substrate film by the followingcoating methods but there is no limitation thereto. Known methods suchas dip coating method, an air knife coating method, a curtain coatingmethod, a roller coating method, a wire bar coating method, a gravurecoating method, a slide coating method, an extrusion coating method (diecoating method) (refer to JP2003-164788 A), and a microgravure coatingmethod may be used and among these, a microgravure coating method and adie coating method are preferable. In a case where the functional filmis formed by a coating method, a drying step of volatilizing a solvent,a thermal crosslinking step of crosslinking a thermally crosslinkinggroup, and a curing step by ionizing radiation irradiation or the likecan be appropriately used.

In a case where the composition for forming a functional film includesthe above-described compound (b) having a reactive group in themolecule, it is preferable to perform a curing step by ionizingradiation irradiation.

In a case where the composition for forming a functional film does notinclude the above-described compound (b) having a reactive group in themolecule and the copolymer (a) and the resin (d) each have a thermallycrosslinking group, it is preferable to perform a thermal crosslinkingstep.

Regarding the drying and curing methods of the functional film,preferable examples thereof will described below.

In the present invention, it is effective to cure the functional film bycombining irradiation with ionizing radiation and a heat treatmentbefore irradiation, simultaneously with irradiation or afterirradiation.

Hereinafter, the time series patterns of several production steps areshown, but the present invention is not limited thereto (the following“-” indicates that the heat treatment is not performed).

Before irradiation→simultaneously with irradiation→after irradiation

(1) Heat treatment→ionizing radiation curing→−

(2) Heat treatment→ionizing radiation curing→heat treatment

(3)−→ionizing radiation curing→heat treatment

Additionally, a step of performing a heat treatment simultaneously withionizing radiation curing is also preferable.

In the present invention, as described above, it is preferable toperform a heat treatment in combination of irradiation with ionizingradiation. The heat treatment is not particularly limited as long as thefunctional film is not damaged, but the temperature is preferably 40° C.to 150° C. and more preferably 40° C. to 110° C.

The time required for the heat treatment varies depending on themolecular weight of components to be used, interaction with othercomponents, viscosity, and the like, but the time required for the heattreatment is 15 seconds to 1 hour, preferably 20 seconds to 30 minutes,and most preferably 30 seconds to 5 minutes.

The kind of the ionizing radiation is not particularly limited. Examplesthereof include an X-ray, an electron beam, an ultraviolet ray, visiblelight, and an infrared ray, and an ultraviolet ray is widely used. Forexample, in a case where the functional film includes an ultravioletcurable component, it is preferable to cure the functional film with anultraviolet lamp at an irradiation dose of 10 mJ/cm² to 1000 ml/cm².From the viewpoint of the adhesiveness between the adhesive layer andthe functional film, the total irradiation dose is more preferably 50mJ/cm² to 1000 mJ/cm².

In the solution film forming method, a solution is prepared bydissolving the material for the functional film in an organic solvent orwater, and the solution is uniformly cast on a support afterappropriately performing a condensation step, a filtration step, and thelike. Next, a half-dry film is peeled off from the support and thesolvent is dried in a drying zone while appropriately gripping both endsof the web with clips or the like. The curing step by ionizing radiationirradiation or the like can also be used appropriately. In addition,stretching can be separately performed during the drying of the film orafter completion of drying and curing of the film.

The thermal crosslinking step is a step of heating for promoting areaction of a thermally crosslinking group, and is not particularlylimited as long as the properties of the functional film are notdamaged. The temperature of the thermal crosslinking step is preferably40° C. to 200° C. and more preferably 50° C. to 130° C. From theviewpoint of facilitating the reaction more easily, the temperature ispreferably 50° C. or higher and from the viewpoint of suppressingdeformation of the resin used in the substrate, the temperature ispreferably 130° C. or lower.

The time required for heating varies depending on the kind and amount ofthermally crosslinking group to be used, but the time required forheating is preferably 5 seconds to 1 hour, more preferably 10 seconds to30 minutes, and even more preferably 15 seconds to 5 minutes. From theviewpoint of facilitating the reaction more easily, the time requiredfor heating is preferably 15 seconds or longer and from the viewpoint ofenhancing productivity, the time is preferably 5 minutes or shorter.

(Substrate Film)

The film thickness of the substrate film used for forming the functionalfilm by a coating method is preferably 5 to 100 μm, more preferably 10to 75 μm, and even more preferably 15 to 55 μm. In a case where the filmthickness is 5 μm or more, sufficient mechanical strength is easilysecured and defects such as curling, wrinkling, buckling and the likeare not easily caused. Thus, this case is preferable. A case where thefilm thickness is 100 μm or less is preferable since for example, in acase where the multilayer film of the functional film of the presentinvention and the substrate film is stored in a long roll rom, it iseasy to adjust the surface pressure applied to the multilayer film to bein an appropriate range and adhesion failure is not easily generated.

The surface energy of the substrate film is not particularly limited,and the adhesive force between the functional film and the substratefilm can be adjusted by adjusting the relationship between the surfaceenergy of the material of the functional film and the coating solutionand the surface energy of the surface of the substrate film on which thefunctional film is to be formed. In a case where the surface energydifference is reduced, the adhesive force tends to increase, and in acase where the surface energy difference is increased, the adhesiveforce tends to decrease, and thus the surface energy can be setappropriately.

The surface energy of the substrate film can be calculated from thecontact angle value between water and methylene iodide using the Owensmethod. For measurement of the contact angle, for example, DM901(contact angle meter, manufactured by Kyowa Interface Science Co., Ltd.)can be used.

The surface energy of the substrate film on which the functional film isto be formed is preferably 41.0 to 48.0 mN/m and more preferably 42.0 to48.0 mN/m. In a case where the surface energy is 41.0 mN/m or more, theuniformity of the thickness of the functional film is enhanced and thusthis case is preferable. In a case where the surface energy is 48.0 mN/mor less, the peeling force between the functional film and the substratefilm is easily controlled to be in an appropriate range and thus thiscase is preferable.

The surface unevenness of the substrate film is not particularly limitedand depending on the relationship between the surface energy, thehardness, and the surface unevenness of the functional film surface, andthe surface energy and hardness of the surface of the substrate filmopposite to the side on which the functional film is formed, forexample, in order to prevent adhesion failure in a case where thefunctional film of the present invention and the substrate film arestored in a long roll form, the surface unevenness of the substrate filmcan be adjusted. In a case where the surface unevenness is increased,adhesion failure tends to be suppressed, and in a case where the surfaceunevenness is reduced, the surface unevenness of the functional filmtends to decrease and the haze of the functional film tends to be small.Thus, the surface unevenness can be set appropriately.

For such a substrate film, known materials and films can beappropriately used. Specific examples of materials include apolyester-based polymer, an olefin-based polymer, a cyclo olefin-basedpolymer, a (meth)acrylic polymer, a cellulose-based polymer, and apolyamide-based polymer.

In particular, the polyester-based polymer and the olefin-based polymerare preferable as the material of the substrate film, thepolyester-based polymer is more preferable, and polyethyleneterephthalate (PET) is particularly preferable among the polyesterpolymers.

For the purpose of adjusting the surface properties of the substratefilm, a surface treatment can be appropriately performed. For example, acorona treatment, a room temperature plasma treatment, a saponificationtreatment and the like can be performed to lower the surface energy, anda silicone treatment, a fluorine treatment, an olefin treatment and thelike can be performed to raise the surface energy.

A releasing agent or the like may be appropriately applied to thesubstrate surface in advance to control adhesiveness with the functionalfilm. The functional film can be used by peeling off the substrate filmafter laminating the functional film on a polarizer through an adhesiveor a pressure sensitive adhesive in a succeeding step. In a state inwhich the functional film is laminated on the substrate film, thefunctional film can be appropriately stretched with the substrate filmand thus optical properties and mechanical properties can be adjusted.

<Laminate>

The substrate on which the functional film is applied is constituted ofat least a substrate and a functional film and is referred to as alaminate as an integrated one.

The laminate allows the functional film to be bonded with other layers,films, or other articles, and particularly allows the functional filmand a polarizer to be bonded through an adhesive layer. In the obtainedpolarizing plate, the substrate can be peeled off from the functionalfilm or can be used as a part of the polarizing plate as it is withoutpeeling. From the viewpoint of reducing the thickness of the polarizingplate, it is preferable to use the functional film after peeling off thesubstrate from the functional film.

(Peeling Force Between Functional Film and Substrate Film)

In a case where the functional film used in the polarizing plate isformed by a coating method, the peeling force between the functionalfilm and the substrate film can be controlled by adjusting the materialof the functional film, the material of the substrate film, the internalstrain of the functional film, and the like. The peeling force can bemeasured in, for example, a test of peeling off the substrate film in adirection of 900, and the peeling force as measured at a speed of 300mm/min is preferably 0.001 to 5 N/25 mm, more preferably 0.01 to 3 N/25mm, and even more preferably 0.05 to 1 N/25 mm. In a case where thepeeling force is 0.001 N/25 mm or more, it is possible to preventpeeling of the substrate film in steps other than the peeling step, andin a case where the peeling force is 5 N/25 mm or less, it is possibleto prevent peeling failure (for example, zipping or cracking of thefunctional film) in the peeling step.

If necessary, a heat treatment step, a superheated steam contact step,an organic solvent contact step, and the like can be performed.

[Polarizing Plate]

A polarizing plate having a polarizer, an adhesive layer, and thefunctional film in this order can be prepared using the functional film.

(Polarizer)

Examples of the polarizer include an iodine-based polarizer and adye-based polarizer using a dichroic dye a polarizer. The iodine-basedpolarizer and the dye-based polarizer may generally be produced using apolyvinyl alcohol-based film. In the present invention, any of thesepolarizers may be used. For example, it is preferable that the polarizeris constituted of a polyvinyl alcohol (PVA) and a dichroic molecule.Regarding the polarizer constituted of a polyvinyl alcohol (PVA) and adichroic molecule, for example, the description of JP2009-237376A can bereferred to. The film thickness of the polarizer may be 1 to 50 μm andis preferably 2 to 30 μm and more preferably 3 to 20 μm.

(Adhesive Layer)

The adhesive layer may be formed from an adhesive. As the adhesive, anadhesive including a resin having a hydroxyl group is preferable, and inaddition to a polyvinyl alcohol-based adhesive, an epoxy-based activeenergy ray curable adhesive, for example, an adhesive which contains anepoxy compound not including an aromatic ring in the molecule asdisclosed in JP2004-245925A and is cured by heating or irradiation withan active energy ray, an active energy ray curable adhesive having (a1)a (meth)acrylic compound having two or more (meth)acryloyl groups in themolecule, (b1) a (meth)acrylic compound having a hydroxyl group in themolecule and having only one polymerizable double bond, and (c1) phenolethylene oxide modified acrylate or nonyl phenol ethylene oxide modifiedacrylate in a total amount of 100 parts by mass of the (meth)acryliccompounds described in JP2008-174667A, and the like may be used. Amongthese, a polyvinyl alcohol-based adhesive is most preferable.

The polyvinyl alcohol-based adhesive is an adhesive including modifiedor unmodified polyvinyl alcohol. The polyvinyl alcohol-based adhesivemay contain a crosslinking agent in addition to the modified orunmodified polyvinyl alcohol. Specific examples of the adhesive includean aqueous solution of polyvinyl alcohol or polyvinyl acetal (forexample, polyvinyl butyral) and a latex of a vinyl-based polymer (forexample, polyvinyl chloride, polyvinyl acetate, or polybutyl acrylate).A particularly preferable adhesive is an aqueous solution of polyvinylalcohol. In this case, it is preferable that polyvinyl alcohol iscompletely saponified.

In addition, the epoxy-based active energy ray curable adhesive can becrosslinked with the copolymer (a) since the epoxy group opens byirradiation with active energy rays to generate hydroxyl groups.Therefore, in the present invention, the epoxy-based active energy raycurable adhesive is also included as a hydroxyl group containingadhesive and can be appropriately used.

[Display Device]

The polarizing plate can be used in a display device. The display deviceis not particularly limited and may be a liquid crystal display deviceincluding a liquid crystal cell, an organic EL image display deviceincluding an organic EL layer, or a plasma image display device. Thepolarizing plate of the present invention can be arranged, for example,on the display surface side. Regarding the configuration of the displaydevice, any configuration of a known display device can be adopted.

EXAMPLES

The present invention will be described in more detail with reference tothe following Examples. The materials, amount of use, ratio, ratio,details of the treatment, procedures of the treatment, and the likeshown in the following Examples can be appropriately changed withoutdeparting from the spirit of the present invention. Therefore, it is tobe understood that the scope of the present invention should not beinterpreted in a limited manner based on the specific examples shownbelow.

Synthesis Example 1

(Synthesis of Fluorine-Containing Copolymer (A-1-1))

A 200 ml three-neck flask equipped with a stirrer, a thermometer, areflux condenser, and a nitrogen gas introduction pipe was changed with10.0 g of cyclohexanone was put into and heated to 84° C. Next, a mixedsolution of 9.00 g (21.5 mmol) of 2-(perfluorohexyl)ethyl acrylate,11.00 g (28.6 mmol) of 4-(4-acryloyloxybutoxy)benzoyloxy phenyl boronicacid, 60.0 g of cyclohexanone, and 1.60 g of “V-601” (manufactured byWako Pure Chemical Corporation) was added dropwise at a constant rate sothat the dropwise addition was completed in 180 minutes. Aftercompletion of the dropwise addition, stirring was further continued for3 hours, then the temperature was raised to 95° C., and stirring wasfurther continued for 2 hours. Thus, 91.0 g of a cyclohexanone solutionof a fluorine-containing copolymer (A-1-1) was obtained. Theweight-average molecular weight (Mw) of the copolymer was 3,600(calculated in terms of polystyrene by gel permeation chromatography(EcoSEC HLC-8320GPC (manufactured by Tosoh Corporation)) under themeasurement conditions of a flow rate of 0.50 ml/min, and a temperatureof 40° C. using an eluent NMP and three columns of TSKgel SuperAWM-H(manufactured by Tosoh Corporation)). In addition, the structure of theobtained copolymer was identified by ¹H-NMR spectrum to determine thecompositional ratio. ¹H-NMR (CDCl₃) δ: 3.8 to 4.5 (2H, 4H, derived froma methylene group of 2-(perfluorohexyl)ethyl acrylate, derived from amethylene group of a repeating unit represented by Compound II-1), 6.8to 7.3 and 7.6 to 8.2 (8H, derived from an aromatic ring of a repeatingunit represented by Compound II-1).

Fluorine-Containing Copolymer (A-1-1)

The fluorine-containing copolymer (A-1-1) includes a repeating unitrepresented by the above structural formula and contains 45% by mass ofa repeating unit derived from 2-(perfluorohexyl)ethyl acrylate withrespect to the total mass of the copolymer and 55% by mass of arepeating unit derived from 4-(4-acryloyloxybutoxy)benzoyloxy phenylboronic acid with respect to the total mass of the copolymer.

Synthesis Examples 2 to 21

Fluorine-containing copolymers (A-2) to (A-18), (A-1-2), (A-1-3), and(A-33) were synthesized in the same manner as in the synthesis of thefluorine-containing copolymer (A-1-1) except that the kind and amount ofmonomers used in Synthesis Example 1 were changed, the amount of thepolymerization initiator was changed to the amounts shown in Table 1below, and the kind and compositional ratio of repeating units in thecomposition to be obtained were changed as shown in Table 1 below.(A-1-1), (A-1-2), and (A-1-3) have the same kind of repeating unit to becontained and have different compositional ratios and different themolecular weights. In addition, a third repeating unit shown in Table 1was further introduced into (A-14) to (A-17).

Synthesis Example 22 (Synthesis Example of Fluorine-Containing Copolymer(A-19-1))

A 500 ml three-neck flask equipped with a stirrer, a thermometer, areflux condenser, and a nitrogen gas introduction pipe was changed with23.3 g of cyclohexanone was put into and heated to 78° C. Next, a mixedsolution of 69.00 g (165.0 mmol) of 2-(perfluorohexyl)ethyl acrylate,16.00 g (41.7 mmol) of 4-(4-acryloyloxybutoxy)benzoyloxy phenyl boronicacid, 15.00 g (208.2 mmol) of acrylic acid, 1,3-propanediol (45.8 mmol),157.7 g of cyclohexanone, 52.5 g of isopropanol, and 5.73 g of “V-601”(manufactured by Wako Pure Chemical Corporation) was added dropwise at aconstant rate so that the dropwise addition was completed in 180minutes. After completion of the dropwise addition, stirring was furthercontinued for 1 hour, then 1.00 g of V-601 was added thereto, and thetemperature was raised to 90° C. Further, stirring was continued for 3hours, and thus 330.0 g of a cyclohexanone solution of afluorine-containing copolymer (A-19-1) of the present invention wasobtained. The weight-average molecular weight (Mw) of the copolymer was5,700 (calculated in terms of polystyrene by gel permeationchromatography (EcoSEC HLC-8320GPC (manufactured by Tosoh Corporation))under the measurement conditions of a flow rate of 0.50 ml/min, and atemperature of 40° C. using an eluent NMP and three columns of TSKgelSuperAWM-H (manufactured by Tosoh Corporation)). In addition, thestructure of the obtained polymer was identified by ¹H-NMR spectrum todetermine the compositional ratio.

¹H-NMR (CDCl₃) δ: 3.8 to 4.5 (2H, 4H, derived from a methylene group of2-(perfluorohexyl)ethyl acrylate, and derived from a methylene group ofa repeating unit represented by Compound II-12, derived from a methylenegroup adjacent to boron of a repeating unit represented by CompoundII-12), 6.8 to 7.3 and 7.6 to 8.2 (8H, derived from an aromatic ring ofa repeating unit represented by Compound II-12).

Fluorine-Containing Copolymer (A-19-1)

Synthesis Examples 23 to 31

Fluorine-containing copolymers (A-19-2), (A-25-1), (A-25-2). (A-23-1),(A-23-2), (A-20), (A-28), (A-29), and (A-19-3) were synthesized in thesame manner as in the synthesis of the fluorine-containing copolymer(A-19-1) except that the kind and amount of monomers used in SynthesisExample 22 were changed, the amount of the polymerization initiator waschanged to the amounts shown in Table 1 below, and the kind andcompositional ratio of the repeating units in the copolymer to beobtained were changed as shown in Table 1 below. (A-19-1), (A-19-2), and(A-19-3) have the same kind of repeating unit and the same compositionalratio and have different molecular weights. (A-23-1) and (A-23-2) havethe same kind of repeating unit and the same compositional ratio andhave different molecular weights. (A-25-1) and (A-25-2) have the samekind of repeating unit and the same compositional ratio and havedifferent molecular weights.

In Table 1, the molecular weight (Mw, Mn) and distribution (Mw/Mn) ofeach of the obtained fluorine-containing copolymers are collectivelyshown. In addition, the amount of the polymerization initiator in Table1 is the amount of the polymerization initiator with respect to thetotal amount of charged monomers expressed by “% by mol”.

TABLE 1 Repeating until Repeating until represented represented AnotherThermally cross- Polymerization by Formula (I) by Formula (II) repeatingunit linking group initiator Molecular Part by Part by Part byFunctional Amount Weight (GPC) Kind mass Kind mass Kind mass group Kind[% by mol] Mw Mn Mw/Mn Synthesis A-1-1 C6FA 45 II-1  55 None — — V-60113.9 3600 1400 2.57 Example 1 Synthesis A-2 C6FA 45 II-2  55 None — —V-601 10.0 3800 1400 2.71 Example 2 Synthesis A-3 C6FA 20 II-3  80 None— — V-601 12.1 4200 1600 2.63 Example 3 Synthesis A-4 C6FA 20 II-4  80None — — V-601 9.9 2800 1200 2.33 Example 4 Synthesis A-5 C6FA 20 II-5 80 None — — V-601 8.5 4600 2200 2.09 Example 5 Synthesis A-6 C6FA 30II-1  70 None — — V-601 14.3 5200 2300 2.26 Example 6 Synthesis A-7C6FHA 25 II-1  75 None — — V-601 12.2 4400 1900 2.32 Example 7 SynthesisA-8 C6FA 30 II-6  70 None — — V-601 12.9 4800 2100 2.29 Example 8Synthesis A-9 C6FA 20 II-7  80 None — — V-601 9.4 4200 1900 2.21 Example9 Synthesis A-10 C6FA 70 II-8  30 None — — V-601 6.6 5900 2200 2.68Example 10 Synthesis A-11 C6FA 40 II-9  60 None — — V-601 18.0 5500 21002.62 Example 11 Synthesis A-12 C6FA 50 II-10 50 None — — V-601 11.1 65002800 2.32 Example 12 Synthesis A-13 C6FA 40 II-11 60 None — — V-601 13.43200 1300 2.45 Example 13 Synthesis A-14 C6FA 45 II-1  25 Si 30 — V-6017.5 5500 1500 3.67 Example 14 Synthesis A-15 C6FA 45 II-1  25 PhOEA 30 —V-601 11.6 10200 4500 2.27 Example 15 Synthesis A-16 C6FA 45 II-1  50 AA 5 COOH V-601 11.3 11200 4400 2.55 Example 16 Synthesis A-17 C6FA 30II-1  25 AS-6S 45 OH V-601 6.0 16000 5600 2.86 Example 17 Synthesis A-18FM-0725 30 II-1  70 None — — V-601 13.7 3600 1500 2.40 Example 18Synthesis A-1-2 C6FA 55 II-1  45 None — — V-601 13.9 3900 1600 2.44Example 19 Synthesis A-1-3 C6FA 70 II-1  30 None — — V-601 14.1 29001300 2.23 Example 20 Synthesis A-33 C6FA 55 BEA 45 None — — V-601 8.54200 1800 2.33 Example 21 Synthesis A-19-1 C6FA 69 II-12 16 AA 15 COOHV-601 6.0 5700 1600 3.56 Example 22 Synthesis A-19-2 C6FA 69 II-12 16 AA15 COOH V-601 0.2 43100 5700 4.07 Example 23 Synthesis A-25-1 C6FA 45II-12 25 SA 30 COOH V-601 6.0 7300 1500 4.87 Example 24 Synthesis A-25-2C6FA 60 II-12 10 SA 30 COOH V-601 0.3 52300 13400 3.90 Example 25Synthesis A-23-1 C6FA 45 II-12 25 PhA 30 COOH V-601 6.0 4600 2200 2.09Example 26 Synthesis A-23-2 C6FA 62 II-12  8 PhA 30 COOH V-601 0.2 4880012600 3.87 Example 27 Synthesis A-20 C6FA 69 II-14 16 AA 15 COOH V-6016.0 5200 1800 2.89 Example 28 Synthesis A-28 C6FA 70 II-12 10 IPOz 20Oxazoline group V-601 7.2 5600 1900 2.95 Example 29 Synthesis A-29 C6FA35 II-12 20 M-100 45 Epoxy group V-601 5.5 8500 2800 3.14 Example 30Synthesis A-19-3 C6FA 60 II-12 11 AA 29 COOH V-601 0.2 43100 10600 4.07Example 31

Abbreviations in Table 1 mean repeating units derived from the followingcompounds.

-   -   C6FHA: 1H,1H,7H-dodecafluoroheptyl acrylate    -   C6FA: 2-(perfluorohexyl)ethyl acrylate    -   C8FA: 2-(perfluorooctyl)ethyl acrylate    -   St: Styrene    -   PhOEA: Phenoxyethyl acrylate    -   AA: Acrylic acid    -   AS-6S: Polystyrene graft type acrylate (manufactured by Toagosei        Co., Ltd.)    -   FM-0725: SILAPLANE FM-0725 (manufactured by JNC Corporation)    -   V-601: Azo initiator (manufactured by Wako Pure Chemical        Corporation)    -   SA: 2-acryloyloxyethyl succinate    -   PhA: 2-methacryloyloxyethyl phthalate    -   BEA: 2-boroxyethyl acrylate    -   IPOz: Isopropenyloxazoline    -   M-100: CYCLOMER M-100 (manufactured by Daicel Corporation)

According to paragraph [0044] of JP2005-248116A and paragraph [0159] ofJP2000-102727A, the following comparative example compounds (H-1) and(H-2) were obtained.

Comparative Example Compound (H-1) (Compound of Example 1 ofJP2005-248116A)

(H-2) (Compound of Example 1 of JP 2000-102727A)

(H-3)

F-552: Commercially available fluorine-based surface modifier (tradename: MEGAFAC F-552, manufactured by DIC Corporation)

[Polystyrene-Based Resin for Functional Film]

Synthesis Example 1P

A 300 ml three-neck flask equipped with a with a stirrer, a thermometer,a reflux condenser, and a nitrogen gas introduction pipe was chargedwith 20.0 g of methyl ethyl ketone, and heated to 80° C. Next, a mixedsolution of 32.0 g of styrene, 8.0 g of CYCLOMER M-100 (manufactured byDaicel Corporation), 20.0 g of methyl ethyl ketone, and 0.04 g of“V-601” (manufactured by Wako Pure Chemical Corporation) was addeddropwise at a constant rate so that the dropwise addition was completedin 3 hours. After completion of the dropwise addition, stirring wasfurther continued for 1 hour, then (1) a solution of 0.01 g of V-601 and1.0 g of methyl ethyl ketone was added thereto, and stirring wasperformed for 2 hours. Subsequently, the step of (1) was repeated twotimes, stirring was further continued for 2 hours, and then the solutionwas poured into 1.5 liters of n-hexane and dried. Thus, 39.5 g ofstyrene-CYCLOMER M copolymer (B-4) was obtained. The weight-averagemolecular weight (Mw) of the polymer was 156200 (calculated in terms ofpolystyrene by gel permeation chromatography (GPC) using columns ofTSKgel SuperHZM-H, TSKgel SuperHZ4000, and TSKgel SuperHZ200(manufactured by Tosoh Corporation)).

<Preparation of Coating Solution for Forming Functional Film>

Coating solutions for forming a functional film 1 to 45 were prepared atcompositions shown Table 2 to 6. In Tables 2 to 6, “%” represents “% bymass”, numerical values in the solvent represent the content of eachsolvent contained in the total amount of the coating solution, andnumerical values in other components represent the contents in thecomponents in the coating solution excluding the solvent.

TABLE 2 Coating Coating Coating Coating Coating Coating Coating CoatingCoating Coating solution solution solution solution solution solutionsolution solution solution solution 1 2 3 4 5 6 7 8 9 10 Component (a)A-1-1  1.0%  1.0% A-1-2  1.0% A-1-3  1.0% A-2 A-3 A-4 A-5 A-6 A-7 A-8A-9 A-10 A-11  1.0% A-12 A-13 A-14 A-15 A-16 A-17 A-18  1.0% A-19-1A-19-2 A-19-3 A-20 A-23-1 A-23-2 A-25-1 A-25-2 A-28 A-29 A-33 H-1  1.0%H-2  1.0% H-3  1.0% Component (b) ADCP   96%   46%   46%   46%   46%  46%   46%   46%   46%   47% Component (c) Irgacure 127   3%   3%   3%  3%   3%   3%   3%   3%   3%   3% Component (d) SGP-10   50%   50%  50%   50%   50%   50%   50%   50%   50% ARTON RX 4500 Compound CEPOCROS RPS-1005 SMA-3840 B-4 Component (e) VYLON 550 Solvent Ethylacetate  100%  100%  100%  100%  100%  100%  100%  100%  100%  100%Toluene Dichloromethane

TABLE 3 Coating Coating Coating Coating Coating Coating Coating CoatingCoating Coating solution solution solution solution solution solutionsolution solution solution solution 11 12 13 14 15 16 17 18 19 20Component (a) A-1-1 A-1-2 A-1-3 A-2  1.0% A-3  1.0% A-4  1.0% A-5  1.0%A-6  1.0% A-7  1.0% A-8  1.0% A-9  1.0% A-10  1.0% A-11 A-12  1.0% A-13A-14 A-15 A-16 A-17 A-18 A-19-1 A-19-2 A-19-3 A-20 A-23-1 A-23-2 A-25-1A-25-2 A-28 A-29 A-33 H-1 H-2 H-3 Component (b) ADCP   46%   46%   46%  46%   46%   46%   46%   46%   46%   46% Component (c) Irgacure 127  3%   3%   3%   3%   3%   3%   3%   3%   3%   3% Component (d) SGP-10  50%   50%   50%   50%   50%   50%   50%   50%   50%   50% ARTON RX4500 Compound C EPOCROS RPS-1005 SMA-3840 B-4 Component (e) VYLON 550Solvent Ethyl acetate  100%  100%  100%  100%  100%  100%  100%  100% 100%  100% Toluene Dichloromethane

TABLE 4 Coating Coating Coating Coating Coating Coating Coating CoatingCoating Coating solution solution solution solution solution solutionsolution solution solution solution 21 22 23 24 25 26 27 28 29 30Component (a) A-1-1 A-1-2 A-1-3 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10A-11 A-12 A-13  1.0% A-14  1.0% A-15  1.0% A-16  1.0%  1.0%  1.0% A-17 1.0% A-18 A-19-1  1.0% A-19-2  1.0% A-19-3  1.0% A-20 A-23-1 A-23-2A-25-1 A-25-2 A-28 A-29 A-33 H-1 H-2 H-3 Component (b) ADCP   46%   46%  46%   46%   46% Component (c) Irgacure 127   3%   3%   3%   3%   3%Component (d) SGP-10   50%   50%   50%   50% 49.5% 49.5% 49.5% 49.5%49.5% ARTON RX 4500 Compound C EPOCROS 49.5%   99% 49.5% 49.5% 49.5%RPS-1005 SMA-3840 B-4 Component (e) VYLON 550 Solvent Ethyl acetate 100%  100%  100%  100%  100%  100%  100%  100%  100%  100% TolueneDichloromethane

TABLE 5 Coating Coating Coating Coating Coating Coating Coating CoatingCoating Coating solution solution solution solution solution solutionsolution solution solution solution 31 32 33 34 35 36 37 38 39 40Component (a) A-1-1 A-1-2 A-1-3 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19-1 A-19-2 A-19-3  0.3%  0.3% 0.3%  10.0%  15.0% A-20  1.0% A-23-1  1.0% A-23-2  1.0% A-25-1  1.0%A-25-2  1.0% A-28 A-29 A-33 H-1 H-2 H-3 Component (b) ADCP Component (c)Irgacure 127 Component (d) SGP-10 49.85% 49.35% ARTON RX 4500 Compound CEPOCROS 49.85% 49.35% 99.70%   90%  85.0%  99.0%  99.0%  99.0%  99.0% 99.0% RPS-1005 SMA-3840 B-4 Component (e) VYLON 550  1.0% Solvent Ethylacetate   100%   100%   100%   100%   100%   100%   100%   100%   100%  100% Toluene Dichloromethane

TABLE 6 Coating Coating Coating Coating Coating solution 41 solution 42solution 43 solution 44 solution 45 Component (a) A-1-1 A-1-2 A-1-3 A-2A-3 A-4 A-5 A-6 A-7   1.0%   1.0% A-8 A-9 A-10 A-11 A-12 A-13 A-14 A-15A-16 A-17 A-18 A-19-1 A-19-2 A-19-3 A-20 A-23-1 A-23-2 A-25-1 A-25-2A-28   1.0% A-29   1.0% A-33   1.0% H-1 H-2 H-3 Component (b) ADCP   46%  46%   46% Component (c) Irgacure 127   3%   3%   3% Component (d)SGP-10   50% ARTON RX 4500   50% Compound C   50% EPOCROS RPS-1005SMA-3840   99% B-4   99% Component (e) VYLON 550 Solvent Ethyl acetate 100%  100%  100% Toluene  100% Dichloromethane  100%

The compounds in Tables 2 to 6 are shown below.

Component (a)

-   -   Fluorine-containing copolymers or comparative example compounds        above

Component (b)

-   -   ADCP: Tricyclodecane dimethanol diacrylate (manufactured by        Shin-Nakamura Chemical Co., Ltd.)

Component (c)

-   -   Irgacure 127: Acylphosphine oxide-based photopolymerization        initiator (manufactured by BASF)

Component (d)

-   -   SGP-10: Polystyrene (manufactured by PS Japan Corporation)    -   ARTON RX 4500: Cyclic olefin-based resin (manufactured by JSR        Corporation)    -   Compound C: Cellulose-based resin    -   EPOCROS RPS-1005: Styrene-oxazoline copolymer (manufactured by        Nippon Shokubai Co., Ltd.)    -   SMA-3840: SMA ester resin (manufactured by KAWAHARA        PETROCHEMICAL CO., LTD.)    -   B-4: Styrene-CYCLOMER M copolymer (synthetic compound in        Synthesis Example 1P above)

Component (e)

-   -   VYLON 550: Polyester-based additive (manufactured by Toyobo Co.        Ltd.)

Solvent

-   -   Ethyl acetate    -   Toluene    -   Dichloromethane

As Compound C, a powder of cellulose acetate having a degree ofsubstitution of 2.86 was used. The viscosity average polymerizationdegree of Compound C was 3(X), the acetyl group substitution degree atthe 6th position was 0.89, the acetone extract content was 7% by mass,the mass average molecular weight/number average molecular weight ratiowas 2.3, the water content was 0.2% by mass, the viscosity in 6% by massdichloromethane solution was 305 mPa·s, the amount of residual aceticacid was 0.1% by mass or less, the Ca content was 65 ppm (parts permillion), the Mg content was 26 ppm, the iron content was 0.8 ppm, thesulfate ion content was 18 ppm, the yellow index was 1.9, and the freeacetic acid content was 47 ppm. The average particle size of the powderwas 1.5 mm, and the standard deviation was 0.5 mm.

<Coating of Functional Film>

A commercially available polyethylene terephthalate film, and LUMIRROR(R) S 105 (film thickness: 38 μm, manufactured by Toray Industries,Inc.) were used as substrates and the coating solutions 1 to 45 wereused to prepare each of functional films 1 to 45. Specifically, eachcoating solution was applied to a substrate under the condition of aconveyance speed of 60 m/min by a die coating method using the slot diedescribed Example 1 of JP2006-122889A. and dried at 100° C. for 60seconds. The coating solutions 1 to 24, 27, and 43 to 45 were furtherirradiated with an ultraviolet ray with an illuminance of 200 mW/cm²,and an irradiation dose of 100 mJ/cm² using an air-cooled metal halidelamp (manufactured by Eye Graphics Co. Ltd.) of 160 W/cm at an oxygenconcentration of about 0.01% by volume under nitrogen purge to cure eachfunctional film. Then, the functional film was rolled up. In thismanner, functional films 1 to 45 were prepared.

The film thickness, contact angle, and equilibrium moisture absorptivityof each of the prepared functional films 1 to 45 were evaluated in thefollowing methods.

<Film Thickness>

The film thickness of the functional film was calculated by measuringthe film thickness of a laminate prepared using a contact type filmthickness meter and subtracting the substrate thickness measured in thesame manner from the film thickness of the laminate. The film thicknessof all of the functional films 1 to 45 was 5.0 μm.

<Contact Angle of Water>

A 3 μL liquid droplet was made in a dry state (20° C., relativehumidity: 65%) at a needle tip using a contact angle meter [“CA-X” typecontact angle meter, manufactured by Kyowa Interface Science Co., Ltd.]and pure water as liquid, and the liquid droplet was brought intocontact with the surface of the functional film to make a liquid dropleton the functional film. The angle on a side including the liquid wasmeasured from the angle formed by a normal line to the liquid surfaceand the functional film surface at a point at which the functional filmand the liquid came into contact with each other in 10 seconds after thedropwise addition and considered as the contact angle. The contact anglewas evaluated based on the results using the following standards.

A: The contact angle was more than 90°.

B: The contact angle was more than 70° and 90° or less.

C: The contact angle was 70° or less.

The evaluation results of all functional films were A and only theevaluation result of the functional film 10 was C. From the results, itis considered that Component (a) above is unevenly distributed on thesurface of the functional films opposite to the surface in contact withthe substrate except for the functional film 10.

<Equilibrium Moisture Absorptivity>

The equilibrium moisture absorptivity was measured in theabove-described method and evaluated based on the following standards.

A: 1.0% by mass or less

B: More than 1.0% by mass and 2.0% by mass or less

C: More than 2.0% by mass

<Preparation of Polarizing Plate>

(Surface Treatment of Film)

A cellulose acetate film (FUJITAC TD40UC, manufactured by FujifilmCorporation) was immersed in 1.5 mol/L of an aqueous solution of sodiumhydroxide (saponification solution) controlled to a temperature of 37°C. for 1 minute and then the film was washed with water. Then, the filmwas immersed in 0.05 mol/L of an aqueous solution of sulfuric acid for30 seconds, and further passed through a water washing bath. Then,draining with an air knife was repeated three times, water dripping wasperformed, and then the film was dried by being retained in a dryingzone at 70° C. for 15 seconds. Thus, a cellulose acetate film which wassubjected to a saponification treatment was prepared.

(Preparation of Polarizer)

According to Example 1 of JP2001-141926A, a difference in acircumferential speed was imparted to two pairs of nip rolls, stretchingwas performed in a longitudinal direction, and thus a polarizer having athickness 12 μm was prepared.

(Lamination)

The polarizer obtained as described above, the functional film, and amaterial of the cellulose acetate film, which was subjected to thesaponification treatment, stored for 3 months in a rolled state wereused. The above-described polarizer was interposed therebetween and thepolarizer and the films were laminated using the following adhesiveshown in Table 7 in a roll-to-roil manner such that the absorption axisof the polarizer was parallel to the longitudinal direction of the film.Here, one surface of the polarizer was set such that the coated surfacewith any one of the functional films 1 to 45 was disposed on thepolarizer side and the other surface of the polarizer was theabove-described cellulose acetate film.

-   -   Adhesive 1:

A 3% by mass aqueous solution of polyvinyl alcohol (PVA-117H,manufactured by Kuraray Co., Ltd.) was used as an adhesive.

In a case of using the adhesive 1, after lamination, curing wasperformed at 70@C for 20 minutes by drying.

-   -   Adhesive 2:

An ultraviolet curable adhesive with the composition shown below wasprepared.

CELLOXIDE 2021P 25 parts by mass ARONOXETANE OXT-221 50 parts by massRIKA RESIN DME-100 25 parts by mass Photoacid generator 1  5 parts bymass

-   -   CELLOXIDE 2021 P:        3,4-epoxycyclohexylmethyl-3,4′-epoxycyclohexane carboxylate        [manufactured by Daicel Corporation]

ARONOXETANE OXT-221:3-ethyl-3-[(3-ethyloxetan-3-yl)methoxymethyl]oxetane [manufactured byToagosei Co., Ltd.]

-   -   RIKA RESIN DME-100: 1,4-cyclohexanedimethanol diglycidylether        [manufactured by Shin-Nihon Kagaku Kogyo Co., Ltd.]    -   Photoacid generator 1: CPI 100P [manufactured by San-Apro Ltd.]

In a case of using the adhesive 2, curing was performed by irradiationwith an ultraviolet ray with an illuminance of 200 mW/cm², and anirradiation dose of 160 mJ/cm² using an air-cooled metal halide lamp(manufactured by Eye Graphics Co., Ltd.) of 160 W/cm under the conditionof 30° C.

The lamination was continued and polyethylene terephthalate as asubstrate was continuously peeled off using the using the same apparatusas the peeling apparatus of a separator to prepare a polarizing plate.

<Evaluation of Adhesiveness of Functional Film and Polarizer>

The adhesiveness between the functional film and the polarizer wasevaluated in the following method. The surface of the polarizing plateon which the functional film was laminated was laminated and fixed tothe glass substrate through an acrylic pressure sensitive adhesivesheet, and then a slit was made between the functional film and thepolarizer with a cutter. The polarizer and the cellulose acetate film atone end of a test piece in a longitudinal direction (one side with awidth of 25 mm) were gripped using a tensile test machine RTF-1210(manufactured by A&D Co., Ltd.) and subjected to a 90-degree peel test(in accordance with JIS K6854-1: 1999 “Adhesives-Determination of peelstrength of bonded assemblies—Part 1: 90° peel”) under an atmosphere ofa temperature of 23° C. and a relative humidity of 60% at a crossheadspeed (grip moving speed) of 300 mm/min, and the evaluation on peelingof the functional film and the polarizer was performed. The stressapplied to peeling was evaluated based on the following standards.

A: Unpeelable (the polarizing plate was broken or peeling occurred atthe interface between the acrylic pressure sensitive adhesive and thefunctional film.)

B: 5.0 N/25 mm or more

C: 2.0 N/25 mm or more and less than 5.0 N/25 mm

D: 0.5 N/25 mm or more and less than 2.0 N/25 mm

E: Less than 0.5 N/25 mm

There is no problem in practical use in the standards A, B, and C. Thestandards A and B are preferable and the standard A is more preferable.

<Punching Inspection of Polarizing Plate Before Mounting on LiquidCrystal Display Device>

The 100 polarizing plates were punched with Thomson blade of 40 mm×40 mmand the state of peeling and cracking of the end surface was observedand evaluated based on the following standards.

A: No peeling and cracking occurred in 100 polarizing plates.

B: Slight peeling or cracking occurred in 1 or more polarizing plates.

C: Peeling or cracking occurred in 5 or more polarizing plates.

There is no problem in practical use in the standards A and B. Thestandard A is preferable.

The evaluation results are shown in Table 7.

TABLE 7 Contact Equilibrium Adhesiveness Punching Coating Functionalangle of moisture between functional inspection of solution filmAdhesive water [°] absorptivity film and polarizer polarizing plateExample 1 1 1 1 A A B A Example 2 2 2 1 A A A A Example 3 2 2 2 A A A AExample 4 3 3 1 A A A A Example 5 4 4 1 A A A A Example 6 5 5 1 A A B BExample 7 6 6 1 A A C B Example 8 11 11 1 A A C B Example 9 12 12 1 A AC B Example 10 13 13 1 A A C B Example 11 14 14 1 A A B A Example 12 1515 1 A A B A Example 13 16 16 1 A A B A Example 14 17 17 1 A A B AExample 15 18 18 1 A A B A Example 16 19 19 1 A A B A Example 17 20 20 1A A B B Example 18 21 21 1 A A C B Example 19 22 22 1 A A B B Example 2023 23 1 A A B B Example 21 24 24 1 A A B B Example 22 25 25 1 A A B AExample 23 26 26 1 A A B A Example 24 27 27 1 A A B B Example 25 28 28 1A A B A Example 26 29 29 1 A A A A Example 27 30 30 1 A A A A Example 2831 31 1 A A A A Example 29 32 32 1 A A A A Example 30 32 32 2 A A A AExample 31 33 33 1 A A A A Example 32 34 34 1 A A B A Example 33 35 35 1A A B A Example 34 36 36 1 A A B A Example 35 37 37 1 A A B A Example 3638 38 1 A A A A Example 37 39 39 1 A A B A Example 38 40 40 1 A A A AExample 39 41 41 1 A A B B Example 40 42 42 1 A A C B Example 41 43 43 1A A C B Example 42 44 44 1 A A B A Example 43 45 45 1 A C B AComparative 7 7 1 A A E C Example 1 Comparative 8 8 1 A A E C Example 2Comparative 9 9 1 A A E C Example 3 Comparative 10 10 1 C A E C Example4

From Table 7, it was found that the polarizing plate of the presentinvention had high adhesiveness between the polarizer and the functionalfilm and excellent processing suitability for punching or the like.

According to the present invention, it is possible to provide acopolymer capable of sufficiently bonding the functional film with otherlayers, films, or other articles, and a composition containing thecopolymer.

While the present invention has been described with reference to thedetailed or specific embodiments, those skilled in the art willrecognize that various changes or modifications can be made withoutdeparting from the spirit and scope of the present invention.

The present application is based on Japanese Patent Application filed onJun. 27, 2016 (JP2016-126440), Japanese Patent Application filed on Sep.30, 2016 (JP2016-193814), and Japanese Patent Application filed on Jan.27, 2017 (JP2017-013698), the contents of which are incorporated hereinby reference.

What is claimed is:
 1. A copolymer comprising: a repeating unitrepresented by the following Formula (I); and a repeating unitrepresented by the following Formula (II),

wherein, in the Formula (I), R¹ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; R² represents an alkyl group having 1to 20 carbon atoms and having at least one fluorine atom as asubstituent, or a group including —Si(R^(a3))(R^(a4))O—; L represents adivalent linking group comprising at least one selected from the groupconsisting of —O—, —(C═O)O—, —O(C═O)—, a divalent aliphatic chain groupand a divalent aliphatic cyclic group; and R^(a3) and R^(a4) eachindependently represent an alkyl group having 1 to 12 carbon atoms whichmay have a substituent,

wherein, in the Formula (II), R¹⁰ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; R¹¹ and R¹² each independentlyrepresent a hydrogen atom, a substituted or unsubstituted aliphatichydrocarbon group, a substituted or unsubstituted aryl group, or asubstituted or unsubstituted heteroaryl group; R¹¹ and R¹² may be linkedto each other; and X¹ represents a divalent linking group.
 2. Thecopolymer according to claim 1, wherein R² of the repeating unitrepresented by the Formula (I) represents an alkyl group having 1 to 20carbon atoms and having at least one fluorine atom as a substituent. 3.The copolymer according to claim 1, wherein the repeating unitrepresented by the Formula (I) is a repeating unit represented by thefollowing Formula (III):

wherein, in the Formula (III), R¹ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; ma and na each independentlyrepresent an integer of 1 to 20; and X represents a hydrogen atom or afluorine atom.
 4. The copolymer according to claim 2, wherein therepeating unit represented by the Formula (I) is a repeating unitrepresented by the following Formula (III):

wherein, in the Formula (III), R¹ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; ma and na each independentlyrepresent an integer of 1 to 20; and X represents a hydrogen atom or afluorine atom.
 5. The copolymer according to claim 1, wherein X¹ of therepeating unit represented by the Formula (II) includes at least onelinking group selected from —(C═O)O—, —O(C═O)—, —(C═O)NH—, —O—, —CO—,—NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂— and has 7 or more carbon atoms.6. The copolymer according to claim 2, wherein X¹ of the repeating unitrepresented by the Formula (II) includes at least one linking groupselected from —(C═O)O—, —O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—,—O(C═O)—NH—, —O(C═O)—O— and —CH₂— and has 7 or more carbon atoms.
 7. Thecopolymer according to claim 3, wherein X¹ of the repeating unitrepresented by the Formula (II) includes at least one linking groupselected from —(C═O)O—, —O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—,—O(C═O)—NH—, —O(C═O)—O— and —CH₂— and has 7 or more carbon atoms.
 8. Thecopolymer according to claim 4, wherein X¹ of the repeating unitrepresented by the Formula (II) includes at least one linking groupselected from —(C═O)O—, —O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—,—O(C═O)—NH—, —O(C═O)—O— and —CH₂— and has 7 or more carbon atoms.
 9. Thecopolymer according to claim 1, wherein the repeating unit representedby the Formula (II) is a repeating unit represented by the followingFormula (V):

wherein, in the Formula (V), R¹⁰ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; R¹¹ and R¹² each independentlyrepresent a hydrogen atom, a substituted or unsubstituted aliphatichydrocarbon group, a substituted or unsubstituted aryl group, or asubstituted or unsubstituted heteroaryl group; R¹¹ and R¹² may be linkedto each other; X¹¹ represents a divalent linking group comprising atleast one selected from the group consisting of —(C═O)O—, —O(C═O)—,—(C═O)NH—, —O—, —CO— and —CH₂—; and X¹² represents a divalent linkinggroup including at least one linking group selected from —(C═O)O—,—O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂—and including at least one substituted or unsubstituted aromatic ring;and a total number of carbon atoms of X¹¹ and X¹² is 7 or more.
 10. Thecopolymer according to claim 2, wherein the repeating unit representedby the Formula (II) is a repeating unit represented by the followingFormula (V):

wherein, in the Formula (V), R¹⁰ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; R¹¹ and R¹² each independentlyrepresent a hydrogen atom, a substituted or unsubstituted aliphatichydrocarbon group, a substituted or unsubstituted aryl group, or asubstituted or unsubstituted heteroaryl group; R¹¹ and R¹² may be linkedto each other; X¹¹ represents a divalent linking group comprising atleast one selected from the group consisting of —(C═O)O—, —O(C═O)—,—(C═O)NH—, —O—, —CO— and —CH₂—; and X¹² represents a divalent linkinggroup including at least one linking group selected from —(C═O)O—,—O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂—and including at least one substituted or unsubstituted aromatic ring;and a total number of carbon atoms of X¹¹ and X¹² is 7 or more.
 11. Thecopolymer according to claim 3, wherein the repeating unit representedby the Formula (II) is a repeating unit represented by the followingFormula (V):

wherein, in the Formula (V), R¹⁰ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; R¹¹ and R¹² each independentlyrepresent a hydrogen atom, a substituted or unsubstituted aliphatichydrocarbon group, a substituted or unsubstituted aryl group, or asubstituted or unsubstituted heteroaryl group; R¹¹ and R¹² may be linkedto each other; X¹¹ represents a divalent linking group comprising atleast one selected from the group consisting of —(C═O)O—, —O(C═O)—,—(C═O)NH—, —O—, —CO— and —CH₂—; and X¹² represents a divalent linkinggroup including at least one linking group selected from —(C═O)O—,—O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂—and including at least one substituted or unsubstituted aromatic ring;and a total number of carbon atoms of X¹¹ and X¹² is 7 or more.
 12. Thecopolymer according to claim 4, wherein the repeating unit representedby the Formula (II) is a repeating unit represented by the followingFormula (V):

wherein, in the Formula (V), R¹⁰ represents a hydrogen atom or an alkylgroup having 1 to 20 carbon atoms; R¹¹ and R¹² each independentlyrepresent a hydrogen atom, a substituted or unsubstituted aliphatichydrocarbon group, a substituted or unsubstituted aryl group, or asubstituted or unsubstituted heteroaryl group; R¹¹ and R¹² may be linkedto each other; X¹¹ represents a divalent linking group comprising atleast one selected from the group consisting of —(C═O)O—, —O(C═O)—,—(C═O)NH—, —O—, —CO— and —CH₂—; and X¹² represents a divalent linkinggroup including at least one linking group selected from —(C═O)O—,—O(C═O)—, —(C═O)NH—, —O—, —CO—, —NH—, —O(C═O)—NH—, —O(C═O)—O— and —CH₂—and including at least one substituted or unsubstituted aromatic ring;and a total number of carbon atoms of X¹¹ and X¹² is 7 or more.
 13. Thecopolymer according to claim 1, wherein R¹¹ and R¹² of the repeatingunit represented by the Formula (II) represent a hydrogen atom.
 14. Thecopolymer according to claim 2, wherein R¹¹ and R¹² of the repeatingunit represented by the Formula (II) represent a hydrogen atom.
 15. Thecopolymer according to claim 3, wherein R¹¹ and R¹² of the repeatingunit represented by the Formula (II) represent a hydrogen atom.
 16. Thecopolymer according to claim 1, further comprising: a thermallycrosslinking group.
 17. The copolymer according to claim 2, furthercomprising: a thermally crosslinking group.
 18. The copolymer accordingto claim 3, further comprising: a thermally crosslinking group.
 19. Acomposition comprising: the copolymer according to claim 1.